Staphylococcus aureus may complicate influenza infection and is seen most frequently in the elderly and intravenous drug users or patients with underlying diseases.

Chest x-ray shows bilateral cavitations. Remember, there is a high incidence of Staphylococcus aureus pneumonia in patients following influenza so in exam if you see a patient with a flu-like illness whose symptoms are now of pneumonia, the likely causative organism is Staphylococcus aureus.

Syphilis is a sexually transmitted infection caused by the spirochaete Treponema pallidum. Acquired syphilis is characterized by primary, secondary, and tertiary stages.

The incubation period is around 3 weeks.

Acquired syphilis :

• Chancre - painless ulcer at the site of sexual contact

• Local non-tender lymphadenopathy

• In women, they are found on the vulva, labia, and, much less frequently, on the cervix.

Secondary features :

• Secondary syphilis often appears 6 weeks after the beginning of the primary lesion but may overlap or not appear for several months.

• Systemic symptoms: Fever, lymphadenopathy, headaches, malaise.

• A generalized polymorphic rash often affects the palms, soles, and face

• Papules enlarge into condylomata lata (pink or grey discs) in moist warm areas.

Tertiary features :

• Gummas (granulomatous lesions can occur in any organ but most commonly affect bone and skin)

• Cardiovascular syphilis ascending aortic aneurysms, aortic regurgitation

• Neurological syphilis tabes dorsalis, dementia.

The symptoms and MRI findings here are highly suggestive of toxoplasmosis, a disease caused by the protozoan Toxoplasma gondii.

The reason behind the HIV history is that toxoplasmosis can reactivate in those with severe HIV disease when their CD4 counts are very low.

Principle manifestations usually include a brain mass lesion, headache, confusion, seizures, and focal neurologic deficits. These symptoms occur due to increased intracranial pressure.

In patients with AIDS, cerebral toxoplasmosis should be right at the top of the list of differentials if one presents with focal neurological symptoms.

Imaging such as a CT or MRI scan of the head would show a "ring" (contrast) enhancing lesion with oedema. Scans may show solitary lesions.

Given the choice of imaging modality, choose an MRI over a CT as MRI appears to be more sensitive than CT in imaging for cerebral toxoplasmosis.

TOXOPLASMOSIS : Toxoplasma gondii is a protozoa that infects the body via the gastrointestinal tract, lung, or broken skin. Human infection occurs from consumption of undercooked meat or, foot or water contaminated with the oocytes.

Its oocysts release trophozoites which migrate widely around the body including to the eye, brain, and muscle.

The usual animal reservoir is cats where oocytes are produced in the cat’s intestines and shed in its faeces. 

This is thought to be an evolutionary adaptation to help toxoplasma gondii complete its life cycle: rats are exposed to cat faeces and are infected with toxoplasma gondii. Most infections are asymptomatic.

Symptomatic patients usually have a self-limiting infection, often having clinical features resembling infectious mononucleosis (fever, malaise, lymphadenopathy). Other less common manifestations include meningoencephalitis and myocarditis.

Treatment: Pyrimethamine plus sulphadiazine.

This patient is suffering from leptospirosis.

Leptospirosis is the most widespread zoonotic infection worldwide. The main risk factor for acquiring the infection is direct or indirect contact with the urine of infected animals. Contact can occur secondary to occupational exposure or accidentally via exposure to unclean sources of water.

Travelers and athletes participating in water sports, such as those who compete in triathlons, represent a growing population at risk. Ask for a history of rowing, fishing, contact with animals, or travel.

The red discoloration of the eye seen initially is subconjunctival hemorrhage which occurs in more than 90% of patients with leptospirosis.

Aminotransferase levels are usually elevated but they are rarely higher than 200 U/L just as seen in this stem. The single most appropriate investigation in this scenario would be blood and urine cultures. This is because leptospirosis can be isolated from blood during the initial phase for the first seven to ten days of the disease.

The Paul Bunnell test or the mono spot test is a form of the heterophile antibody test. It is a rapid test for infectious mononucleosis due to the Epstein-Barr virus (EBV). This choice is therefore incorrect.

This patient is having meningitis. Treatment for meningitis should be started before doing any investigations due to the seriousness of the disease. In a hospital setting, give intravenous third-generation cephalosporin antibiotics (ceftriaxone or cefotaxime).

Hepatitis B surface antigen (HBsAg) is a marker of acute hepatitis B infection and the first abnormal serological test.

Hepatitis B e antigen (HBeAg) and Hepatitis B DNA also appear soon after. The presence of HBeAg in the serum of patients can serve as a marker of active replication.

Hepatitis B core IgM antibody indicates recent infection with hepatitis B virus (< 6 months). It appears shortly after the onset of symptoms and at a similar time to the rise in alanine aminotransferase (ALT).

The presence of anti-hepatitis B e antibody (HbeAb) is a sign that the patient has moved into a non-replicative stage of chronic hepatitis B – usually due to treatment. It is not used as a marker of acute hepatitis B.

Hepatitis B is a DNA virus spread through contact with infected bodily fluids.

Key summary of the most commonly asked hepatitis B serology that is a must-know for the exam:

• HBsAg positive – Infection acute or chronic

• HbsAg positive and HbeAg positive – Highly infectiousness

• HBsAg positive alone – Recent vaccination

• Anti-HBc positive – Past infection

At first, the impression that is given in the stem points towards Pneumocystis jiroveci given the history of cough and an HIV-positive patient. Pneumocystis jiroveci is the most common opportunistic infection in HIV-positive patients.

However, one must remember that Pneumocystis jiroveci tends to affect HIV-positive patients who have a CD4 count below 200 cells/mm³. For this reason, all patients with a CD4 count < 200/mm³ should receive Pneumocystis jiroveci prophylaxis.

While it is true that Pneumocystis jiroveci can also infect an HIV-positive patient with a CD4 count above 200 cells/mm³, it is less likely compared to Streptococcus pneumoniae.

The chest X-ray findings also point more toward Streptococcus pneumoniae as the causative organism. Remember that Streptococcus pneumoniae is the most common causative organism of lobar pneumonia and it accounts for around 80% of cases of community-acquired pneumonia (CAP).

Note that, HIV infection is also a risk factor for Streptococcus pneumoniae infections.

Immunocompetent patients require treatment if symptoms of toxoplasmosis are severe and persistent. Pyrimethamine is the most effective agent for toxoplasmosis infections. This is given in combination with sulfadiazine. Sometimes clindamycin is used instead of sulfadiazine.

Lyme disease is caused by the spirochaete Borrelia burgdorferi and is spread by ticks. Tick needs at least 24 hours of attachment to transmit the Borrelia burgdorferi organism.

Symptoms begin 3-30 days after the bite of the tick. Patients develop the erythema migrans rash at the site of the bite. (An erythematous patch, which may enlarge in the first few days).

Even without treatment, the rash resolves in several weeks. A flu-like illness with fever, chills, and myalgias occurs in half of patients. Neurologic symptoms develop several weeks later. This is most commonly paralysis of the seventh cranial nerve (facial paralysis) and may be bilateral.

Meningitis and encephalitis may develop as well. Cardiac symptoms develop and are most commonly an AV heart block or Myocarditis. Joint involvement may develop but this is months to years later.

Investigation :

Serology: Antibodies to Borrelia burgdorferi

Management :

• Doxycycline if early disease. Amoxicillin is an alternative if doxycycline is contraindicated (e.g. pregnancy)

• Ceftriaxone if a disseminated disease.

Ramsay Hunt syndrome (herpes zoster oticus) is caused by the reactivation of the varicella-zoster virus in the geniculate ganglion of the seventh cranial nerve.

Features :

• Auricular pain is often the first feature

• Facial nerve palsy (ipsilateral facial palsy, loss of taste)

• Painful vesicular rash around the ear on the auditory canal

• Vertigo and tinnitus

• Ipsilateral hearing loss

Management :

• Oral acyclovir and corticosteroids are usually given

• For herpetic neuralgia, give amitriptyline for the pain.

This is typical for oral candidiasis.

White patches in the mouth can be easily removed, leaving an underlying red base that is usually painless.

PSEUDOMEMBRANOUS ORAL CANDIDIASIS (ORAL THRUSH) :

• Curd-like white patches in the mouth

• White pseudomembrane can be easily removed, leaving an underlying red base that is usually painless (in contrast with leukoplakia, which cannot be rubbed off)

• Cracks can occasionally be seen at the corners of the mouth

Predisposing factors :

• Inhaled corticosteroids – risk can be decreased by using large volume spacer or mouthwash after use.

• Diabetes mellitus

• Recent use of broad-spectrum antibiotics

• Elderly with false teeth

Treatment :

• Oral fluconazole

• NICE CKS recommends using miconazole oral gel as first-line or nystatin suspension if the infection is mild and localized.

In exam, when you see an elderly living in a nursing home with rashes, think of scabies Permethrin 5% is probably the only treatment that would be asked in exam for scabies.

Scabies is a parasitic skin infection characterized by superficial burrows, intense pruritus, and secondary infections Aetiology Sarcoptes scabiei. Transmitted by skin-to-skin contact.

Clinical Findings : Pruritus, burrows, papules, commonly found on flexor surfaces of wrists, finger webs, elbows, axillary folds, areola of the breast in women, and genitals of the males. Scabies dig into the skin at the skin folds.

• Patients who are immunocompromised or debilitated may develop a severe form of scabies called Norwegian scabies (crusted scabies). These patients present with diffuse cutaneous involvement with crusting and malodorous discharge.

Treatment :

• Scabies treatment is with permethrin 5% which is first-line

• Malathion 0.5% is second-line

• Note: All household and close physical contacts should be treated at the same time, even if asymptomatic.

Please see Q - 10

Even though the measles, mumps, and rubella (MMR) vaccine contains live attenuated viruses, it is sometimes recommended for people with HIV/AIDS. It is contraindicated if the patient is severely immunocompromised including an HIV-infected patient with CD4 counts less than 200 cells/mL (or less than 750 cells/mL in children).

Here is a summarized list of the presentation of these diseases.

Remember to tie in the signs and symptoms with the travel history :

• Malaria: fever, chills, rigors

• Dengue Fever: generalized rash, biphasic fever, retro-orbital pain

• Typhoid: severe headache, patients adopt a crouching position

• Diphtheria: presents with flu-like symptoms initially, enlarged anterior cervical lymph nodes.

Annular rash is seen in Lyme disease.

BCG should not be given to HIV-positive patients. All other vaccinations can be given. MMR vaccinations should not be given if the CD4 count is below 200 cells/mL.

As the question stem does not state the CD4 count, administering all vaccines as scheduled except the BCG vaccine is most appropriate.

There are debates about avoiding live immunization for HIV in children however it is best to follow the guidelines.

The two vaccines that HIV-positive patients should NOT have (regardless of CD4 count) are: BCG & Yellow fever.

Sore throat and cervical lymphadenopathy are some of the main features of infectious mononucleosis. If this was an HIV infection, there would be more of a generalized lymphadenopathy.

Infectious mononucleosis (glandular fever) is caused by the Epstein-Barr virus (also known as human herpesvirus 4, HHV-4). It is most common in adolescents and young adults.

Features :

• Sore throat; tonsillar enlargement is common, classically exudative and maybe massive

• Palatal petechiae

• Lymphadenopathy, especially neck glands

• Pyrexia

• Malaise

• Splenomegaly - may rarely predispose to splenic rupture

• A maculopapular, pruritic rash develops in around 99% of patients who take ampicillin/amoxicillin whilst they have infectious mononucleosis. Thus, they should not be given to any patient who might have infectious mononucleosis.

Diagnosis :

• Heterophil antibody test (Monospot test / Paul Bunnell)

Other investigations :

• FBC

• Raised white cell count with lymphocytosis and a relative atypical lymphocyte count greater than 20%

• ESR is elevated

- Management is supportive. Simple analgesia for any aches or pains.

Angular cheilitis

• Redness, fissuring, and soreness at the angle of the mouth.

• It can be due either to Candida spp. or to bacterial infection (mainly S. aureus)

• Contributing factors are older age, ill-fitting dentures, immunocompromised, vitamin B12 deficiency, or iron-deficiency anaemia.

A full course of DPT vaccine would be appropriate to prevent tetanus in the future. Children aged under 10 years if miss the vaccine can resume the schedule with the primary immunization (first 3 doses). There should be a minimum of one month between doses of the vaccine.

This is then followed by the first booster immunization which is 3 years after primary immunization in children under 10 years of age. The second booster immunization is given 10 years after the first booster.

TETANUS PROPHYLAXIS :

Tetanus vaccine is currently given as part of the routine immunization schedule at:

• 2 months

• 3 months

• 4 months

• 3-5 years

• 13-18 years

If high-risk wound - Give intramuscular tetanus immunoglobulin irrespective of whether 5 doses of tetanus vaccine have previously been given.

If incomplete or unknown vaccination - Give a complete course of tetanus vaccine.

What is considered a high-risk wound?

• Wounds contaminated with soil

• Compound fractures

• Wounds containing foreign bodies

• Wounds or burns in people with systemic sepsis. After the 5th dose of the tetanus vaccine, immunity is considered for life and you do not need any further boosters.

She has signs of meningitis. If you suspect meningitis and the patient is not yet in the hospital give IM benzylpenicillin and send the patient to the hospital urgently. In a hospital setting, give intravenous third-generation cephalosporin antibiotics.

If this same question was given, but there was a diagnosis of Listeria, then IV amoxicillin and gentamicin would be the correct answer.

If this same question was given, but she is penicillin or cephalosporin allergic, then chloramphenicol would be the answer.

Investigations :

Generally, treatment for meningitis should be started before doing any investigations due to the seriousness of the disease. Rash If the patient has a rash, then perform a blood culture as the diagnosis is most likely meningococcal septicemia. The causative organism is Neisseria meningitides.

If there is no rash then a lumbar puncture would be a better answer, but this can only be done if there are no signs of raised intracranial pressure (ICP).

Patients with increased ICP from mass lesions often display decreased levels of consciousness, focal neurological signs, or papilloedema on physical exams. 

A maculopapular, pruritic rash develops in around 99% of patients who take ampicillin / amoxicillin whilst they have infectious mononucleosis.

Genital herpes simplex which is caused by herpes simplex virus may present with painful multiple ulcers and also dysuria.

Syphilis ulcers are usually painless and thus is not the correct answer.

GENITAL HERPES :

May be asymptomatic or may remain dormant for months or even years. When symptoms occur soon after a person is infected, they tend to be severe. They may start as multiple small blisters that eventually break open and produce raw, painful sores that scab and heal over within a few weeks.

The blisters and sores may be accompanied by flu-like symptoms with fever and swollen lymph nodes. Often also accompanied by dysuria. Genital herpes can be a chronic, lifelong infection. 

HSV-1 was known for its orolabial herpes (cold sores) and HSV-2 for its genital herpes. But now, HSV-1 is the most common cause of both orolabial herpes and genital herpes.

Signs: Flu-like prodrome, then grouped vesicles/papules develop around genitals. These burst, and form shallow ulcers.

Management: Oral acyclovir. Some patients with frequent exacerbations may benefit from longer-term acyclovir.

A temperature of more than 38 C and neutrophil count of less than 0.5 x 109/L defines neutropenic sepsis.

NEUTROPENIC SEPSIS :

Neutropenic sepsis is a potentially fatal complication of chemotherapy.

Febrile neutropenia is defined as:

• An oral temperature 38.5°C or two consecutive readings of  38.0°C for two hours and

• An absolute neutrophil count of 0.5 x 109/L

Chemo is the most common cause of neutropenic sepsis

General Management for Neutropenic Sepsis :

• Antibiotics must be started immediately (do not wait for the WBC)

• Start intibiotic therapy with piperacillin with tazobactam immediately

If uncertain history of previous vaccination and high-risk wound (like in this case), give vaccine and tetanus immunoglobulin (TIG). This should be a complete course.

A maculopapular, pruritic rash develops in around 99% of patients who take ampicillin/amoxicillin whilst they have infectious mononucleosis.

The clincher here is the positive Paul Bunnell test which is only seen in infectious mononucleosis (Glandular fever).

The rest of the symptoms fit perfectly as well. Palatal petechiae and sore throat can occur with infectious mononucleosis. WBCs are classically high and the anaemia is secondary to cold agglutinins (IgM).

The probable diagnosis here is Genital Herpes Simplex.

Usually, Viral culture and DNA detection using polymerase chain reaction (PCR) of a swab from the base of an ulcer are used to diagnose genital herpes. Now NAAT testing is the preferred diagnostic modality above PCR-based methods but both NAAT testing and PCR-based methods are more sensitive than viral culture.

Anti-HSV antibodies are only used in certain scenarios. One of them is if there are recurrent/atypical genital ulcers with negative culture or PCR results. Remember, serum HSV-specific antibodies should not be routine as this blood test cannot reliably differentiate between a recent or a previous infection. It may be helpful in specific situations like in this case.

This patient has the typical symptoms of pneumonia as well as the presence of herpes labialis. That, in addition to the consolidation seen on the chest X-ray, is very suggestive of a streptococcal infection which is a gram-positive diplococci (found in pairs).

Streptococcus pneumoniae is the commonest bacterial pneumonia and one of the clinical features that separates it from the rest of pneumonias is herpes labialis.

Kaposi's sarcoma (KS) is a connective tissue cancer caused by human herpesvirus 8 - now called Kaposi's sarcoma-associated herpesvirus (KSHV). The malignant lesion is characterized by neoplastic cells and abnormally growing blood vessels.

KS is different from other neoplasms because lesions may begin in more than one place at the same time.

Types of Kaposi's sarcoma:

1. Classic: especially elderly Jewish or Mediterranean man. It is rare and progresses slowly over the years.

2. Endemic or African KS: affects young adult men who live near the African equator and have a normal immune system.

3. KS in immunosuppression: Aggressive course with visceral involvement.

4. AIDS-related: May be life-threatening with many skin, gut, and lung lesions.

- It affects mostly homo- or bisexual men

Presentation :

• Skin lesions may be nodular, papular, or blotchy; they may be red, purple, brown, or black.

• Lesions can also be seen under or on mucous membranes, with similar characteristics.

• The most common sites include the mouth, nose, and throat.

• Usually painless but may become painful if inflamed or swollen.

• Lesions may also involve internal organs - eg, lungs (leading to dyspnoea), gastrointestinal tract (it can cause fatal bleeding), and lymphatics, resulting in lymphoedema.

The standard unsupervised six-month treatment regimen may be used during pregnancy. Streptomycin should not be used in pregnancy because it has been shown to have harmful effects on the fetus. This patient should be treated as the risks of untreated tuberculosis are greater in pregnancy than in the medication.

The risk of the pregnancy are perinatal infection, low birth weight or growth retardation, and premature delivery.

Treatment for tuberculosis is the same for pregnant and non-pregnant status: 4 drug therapy (Isoniazid, Rifampicin, Pyrazinamide, Ethambutol).

There are clear signs of infection with the risk that the patient could be having neutropenic sepsis thus broad spectrum IV antibiotics should be started empirically while waiting for blood reports.

There are 2 main reasons neutropenia is seen in lymphoma:

1. Lymphoma in the bone marrow

• If lymphoma cells are in the bone marrow, they take up space that is normally used to produce healthy blood cells which can lead to neutropenia.

2. Side effects of treatment

• Although treatment aims to kill the lymphoma cells, a side effect of many types of chemotherapy, and some radiotherapy treatments (eg radiotherapy to the pelvis), is that some healthy cells are also destroyed.

This may include blood cells that are developing in the bone marrow.

• Depending on the strength of your chemotherapy regimen, neutropenia is most commonly seen 10 to 14 days after chemotherapy.

A single painful ulcer is likely to be Chancroid, caused by Haemophilus ducreyi. The pain inguinal lymphadenopathy is also typical.

As the saying goes, “You do cry with ducreyi”.

Primary syphilis typically causes a painless ulcer (chancre). Herpes simplex virus (HSV) leads to several inflamed papules and vesicles.

It would be uncommon to have a single ulcer. In addition, the presence of HSV antibodies does not confirm the diagnosis (only past exposure), as many patients will acquire the infection but remain asymptomatic. Blood and urine cultures are not required.

Meningococcal Prophylaxis -

Prevention of secondary cases of meningococcal meningitis is with rifampicin or ciprofloxacin. It is usually given to all intimate, household, or daycare contacts who have been exposed to the patient within 10 days of onset.

The therapy after identification of Listeria monocytogenes in CSF is ampicillin 2g 4 hourly + gentamicin 5 mg/kg divided into 8-hourly doses.

This is likely a case of a common cold. No further investigations or management is required.

This lady has been taking malaria chemoprophylaxis but it is important to note that Malaria can still occur in people even though they take Malaria chemoprophylaxis. Chloroquine and proguanil can be used in pregnancy but these drugs are not appropriate for most areas because their effectiveness has declined, particularly in Sub-Saharan Africa.

Key message: Chloroquine and proguanil are safe in pregnancy, but they are no longer efficacious in areas of chloroquine resistance.

Mefloquine is now the drug of choice and recommended by the Royal College of Obstetricians and Gynaecologists (RCOG) for prophylaxis in pregnant women in the second and third trimester traveling to chloroquine-resistant areas.

Evidence also suggests that pregnant women are twice as likely as non-pregnant women to be bitten by anopheline mosquitoes which is the reason we should encourage women not to travel to areas with malaria.

Clinical features that are seen with Malaria include:

• Intermittent fevers

• Chills

• Rigors

• Headache

• Cough

• Myalgia

• Gastrointestinal upset

• Splenomegaly

• Hepatomegaly

• Jaundice

The diagnosis here is chicken pox. The management here would involve reassurance, and supportive management like paracetamol for the fever, antihistamine, and calamine lotion for the pruritus. There is no role of acyclovir in a healthy child or adult.

Antibiotics are administered only in the case of superimposed infection.

Chickenpox :

• Caused by primary infection with varicella-zoster virus. Reactivation of the dormant virus after a bout of chickenpox leads to herpes zoster (shingles)

• Highly infectious and its spread is via the respiratory route. Most chickenpox is mild to moderate and self-limiting but serious complications can occur in immunocompromised patients. 

Clinical features :

• Pyrexia : Often the first feature

• Itchy, rash starting on the head, chest, and back before spreading

• Lesions are usually most concentrated on the chest and back

• Initially rash is macular then papular then vesicular then dry crust

Clinical features tend to be more severe in adults

Management :

• Pruritus managed by sedating antihistamines and emollients. While some sources mention that calamine lotion is no longer recommended, as when it dries it ceases to be effective, it is still used and the advice that is given is to reapply it regularly.

• Administer varicella zoster immunoglobulin (VZIG) to: Immunocompromised with exposure or Newborn with peripartum exposure or Pregnant women with exposure and with no varicella antibodies.

• Administer acyclovir to: Pregnant women who develop chickenpox. Immunocompromised who develop chickenpox.

When you see an elderly living in a nursing home with rashes, think of scabies. Permethrin 5% is probably the only treatment that would be asked in exam for scabies.

Remember that there is no specific treatment for mumps but drugs such as paracetamol and ibuprofen may give symptomatic relief. In this case, reassurance is all that is needed. Mumps is a self-limiting condition.

Mumps :

• Mumps is an acute, generalized infection caused by a paramyxovirus, usually in children and young adults

• It can infect any organ but usually affects the salivary glands

• The virus is highly infectious with transmission by droplets spread in saliva via close personal contact

• Infected persons excrete the virus for several days before symptoms appear and for several days afterward

Presentation :

• Mumps can be asymptomatic

• Nonspecific symptoms lasting a few days, such as fever, headache, malaise, myalgia, and anorexia, can precede parotitis

• Parotitis is usually bilateral although it can be unilateral

• Typically, there is pain at or near the angle of the jaw

• Fever may be as high as 39.5°C without rigors in small children

• Swelling causes distortion of the face and neck with skin over the gland hot and flushed but there is no rash

• With severe swelling, the mouth cannot be opened and is dry because the salivary ducts are blocked.

• Discomfort lasts for three or four days but may be prolonged when one side clears and the other side swells

• Usually just the parotid glands are involved but, rarely, the submaxillary and sublingual salivary glands are affected Orchitis. Orchitis may occur four or five days after the start of parotitis but it often appears without it. This can sometimes lead to the diagnosis being missed.

Orchitis presents with chills, sweats, headache, and backache with swinging temperature and severe local testicular pain and tenderness. The scrotum is swollen and oedematous so that the testes are impalpable. Orchitis is usually unilateral but may be bilateral.

Necrotizing fasciitis is a life-threatening infection that rapidly spreads caused predominantly by group A-hemolytic Streptococci. It is defined as a necrotizing infection involving any layer of the deep soft tissue compartment (dermis, subcutaneous tissue, fascia, or muscle).

Risk factors :

• Intramuscular or subcutaneous drug injection

• Diabetes

• Immunosuppression

Presentation according to days :

• Day 1 to 2 - Swelling, erythema, pain over the affected area (mimics cellulitis)

- Margins of infection are poorly defined, with tenderness extending beyond the apparent area of involvement (unlike cellulitis)

- No response to antibiotics (unlike cellulitis)

• Day 2 to 4 - Bullae, indicating skin ischaemia (unlike cellulitis). Skin progresses to grey colour due to necrosis (unlike cellulitis). Subcutaneous tissues have a wooden-hard feel (unlike cellulitis). From intense pain to anaesthesia-like pain due to nerves being destroyed.

• Day 4 to 5 - Septic shock develops. As necrotizing infection is deep within the skin and is not visible, it is often difficult to diagnose. One important notable feature is if the pain is severe, and disproportionate to the physical signs, think necrotizing fasciitis.

HbsAg-negative; anti HBc-negative; anti-HBs-negative : Susceptible

HbsAg-negative; anti-HBc-positive; anti-HBs-positive : Immune due to natural infection

HbsAg-negative; anti-HBc-negative; anti-HBs-positive : Immune due to Hep-B vaccination

HbsAg-positive; anti HBc-positive; IgM anti-HBc-positive; anti-HBs-negative : Acutely infected

HbsAg-positive; anti HBc-positive; IgM anti-HBc-negative; anti-HBs-negative : Chronically infected

Malaria prophylaxis does not provide full protection against all subtypes of malarial parasites. The two top choices given here are cerebral malaria and meningococcal meningitis.

The full blood count showing anaemia points towards cerebral malaria as the diagnosis rather than meningococcal meningitis. Impaired consciousness is one of the signs of cerebral malaria.

There are no specific symptoms of malaria so it is critical to consider the possibility of the diagnosis.

The diagnosis here is chicken pox. It is caused by the varicella-zoster virus. The mode of transmission of the varicella-zoster virus is mainly person-to-person by airborne respiratory droplets but also occurs by direct contact with the vesicle fluid of chickenpox cases or contact with the vesicle fluid of patients with herpes zoster.

Bladder involvement is caused by Schistosoma haematobium while Schistosoma mansoni is mainly responsible for intestinal forms of disease. Urinary schistosomiasis (bilharzia). This is caused by the parasitic trematode (or flatworm) called Schistosoma haematobium. It occurs in Africa, Egypt and the Middle East.

In scabies, pruritus develops as an allergic reaction to infection, around 4-6 weeks after infestation. Most of the symptoms of scabies are due to your immune system's response to the mites, their saliva, their eggs, or their faeces. In other words, the rash and the itching are mostly caused by your body's allergic-like reaction to the mites, rather than the mites themselves.

Chlamydia is the sexually transmitted infection and is caused by Chlamydia Trachomatis.

Males tend to have either:

• Classical urethritis with dysuria and urethral discharge 

• Epididymo-orchitis presenting as unilateral testicular pain

* Fever may also be a presenting feature in males.

It is important to remember the risk factors of tuberculosis as well as how it presents. Weight loss is seen in tuberculosis. One of the signs of tuberculosis is lymphadenopathy particularly cervical which is seen in this stem.

The examination findings and chest X-ray are consistent with almost every option given in the question. But only tuberculosis and lung cancer would have the associated weight loss. Given the age of only 23, tuberculosis is the likely answer.

Risk factors for TB which are included in this stem are:

• Homeless

• Drug abuser

• Smoker

The reason for homeless and drug abusers being at risk of TB is that they often live in overcrowded areas and have poor housing which encourages the spread of TB.

TUBERCULOSIS (TB) is an infection caused by Mycobacterium tuberculosis that most commonly affects the lungs.

Primary tuberculosis :

• Primary infection of the lungs

• A small lung lesion known as a Ghon focus develops

• Primary infection is usually asymptomatic

Secondary (post-primary) tuberculosis :

• Occurs if the host becomes immunocompromised the initial infection may become reactivated

• Presentation of secondary infection is variable and often nonspecific

Presentation :

• Fatigue, malaise

• Chronic, productive cough

• Night sweats

• Weight loss

Diagnosis :

• X-ray The upper lobe infiltrates with cavitation

• Stain for Acid-Fast Bacilli (AFB)

• Culture is most specific but may take weeks

• Nucleic acid amplification test. Only performed as an additional test in specific scenarios such as if the patient has HIV, or rapid information about mycobacterial species would alter the management. Do not use the Mantoux test to diagnose acute cases of TB Screening

• Mantoux testing to diagnose latent tuberculosis infection.

• Interferon Gamma testing : Used in patients who have had a bacillus Calmette-Guérin (BCG) vaccine. This is because the Mantoux test may be positive in patients who have had a BCG vaccine.

Management of active tuberculosis :

• Initial phase - first 2 months. Mnemonic (RIPE): Rifampicin,  Isoniazid, Pyrazinamide, Ethambutol

• Continuation phase - next 4 months. Rifampicin, Isoniazid  

Tuberculous lymphadenitis (or tuberculous adenitis) is a chronic specific granulomatous inflammation of the lymph node with caseation necrosis, caused by infection with Mycobacterium tuberculosis or Mycobacterium bovis.

Tuberculosis is responsible for up to 43 percent of peripheral lymphadenopathy in the developing world. In rural India, the prevalence of tuberculous lymphadenitis is significantly higher.

Piperacillin-Tazobactam may be used in the management of neutropenic patients with fever suspected to be due to a bacterial infection as in patients with post-chemotherapy neutropenia.

The fever, headache, vomiting, and drowsiness are nonspecific but given there is absent history of symptoms of a urinary tract infection or respiratory infection, we should consider CNS involvement. The key phrase here is also photophobia which makes meningitis the top of your list of which a lumbar puncture is the method of choice for diagnosis.

For exam, a good trick which works most of the time is if the patient has got a rash, then perform blood culture as the diagnosis is most likely meningococcal septicaemia.

The causative organism is Neisseria meningitides. If there is no rash then a lumbar puncture (LP) would be the answer, but this can only be done if there are no signs of raised intracranial pressure (ICP).

Lumbar puncture contraindications to look out for during the exam:

• Glasgow Coma Scale less than 9 or a drop of 3 points or more

• Papilloedema

• Unequal, dilated or poorly responsive pupils

• Bulging tense fontanelle.

Do not get distracted by the itch that is worse at night following a bath. Although we see that commonly in polycythemia, the greyish-white linear rash on the wrist points towards scabies.

Please see Q-40

Schuffner’s dots are exclusively found in Plasmodium ovale and Plasmodium vivax. Thus primaquine should be used to eradicate them. The fact that they gave you the ethnicity, is another clue. Plasmodium ovale typically comes from Africa.

The patient is at risk of acquiring a blood-borne viral infection such as hepatitis B, hepatitis C, and HIV. The assaulter is known to be a drug addict and therefore is at a higher risk of being infected with a blood-borne virus. This wound is considered high-risk, and post-exposure prophylaxis (PEP) should be started.

Testing for hepatitis B, hepatitis C, and HIV initially is recommended as a baseline test. This gives us clues to whether the police officer is already positive for HIV in which case the management differs. But the more important action is to start PEP as this can significantly change the outcome of the incident.

The police officer will also require follow-up serology blood tests at 6 weeks, 3 months, and 6 months.

All human bites should be treated with a 7-day course of oral co-amoxiclav.

Clues that point to tuberculosis in this stem are cachexic, chronic cough, and hemoptysis. The chest X-ray findings are also consistent with tuberculosis. In tuberculosis, the chest X-rays usually show upper lobe infiltrates with cavitation. Although marijuana is in the stem, smoking marijuana is not an independent risk factor for developing tuberculosis.

The patient would be asked to produce 3 samples of a deep cough sputum (with at least 1 early morning sample) and these are sent away for acid-fast staining and culture. Pleural aspiration as a diagnostic procedure is usually performed in unilateral pleural effusions where there is diagnostic uncertainty. Pleural aspiration is not routinely used as a diagnostic procedure for tuberculosis although it can detect TB.

Superficial neck abscesses are usually the result of an infection in a lymph node in the neck (lymphadenitis) turning into an abscess. Staphylococcus aureus is usually the culprit.

Antibiotics can initially be given and if the abscess does not resolve then it may need to be drained. However, given this stem, it is clear that she is unwell and possibly septic, and thus oral antibiotics would not be a good option here. Antibiotics need to be given intravenously, and the abscess needs to be drained.

Most cases of neck abscess require patients to be hospitalized and intravenous antibiotics to be given. Analgesia is also important to relieve pain from the abscess but the option to give oral antibiotics in combination with pain relief is an incorrect one in a scenario where the patient is potentially septic.

Draining of a superficial neck abscess is a simple procedure and is done under general anesthesia. Incision and drainage are important as the pus sample collected from the drainage is sent to the laboratory for culture and sensitivity. After the organism is identified, specific antibiotics can be used accordingly.

Smokers are more likely to develop oral thrush. The history of pregnancy is not too relevant. But the idea that the question writers want to portray is that in pregnancy, the immune system is weakened. Thus candidiasis is more likely. Lichen planus may have a lace-like appearance and not a thick white mark like in this case.

Aphthous ulcers are typically round or oval sores or ulcers inside the mouth. Molluscum contagiosum is present as firm, smooth, umbilicated papules on the trunk or extremities and not in the mouth like in the given stem. Leukoplakia is an option but it is less likely that oral candidiasis. They may sometimes give a history of a white lesion in the mouth that cannot be rubbed off.

Please see Q-10

Infectious mastitis occurs when accumulated milk allows bacteria to grow. It typically develops within the first few weeks of breastfeeding. If treatment is delayed it may result in a breast abscess like in this case. The usual infecting organism is Staphylococcus aureus, although it may also be caused by Staphylococcus albus and streptococci.

If a breast abscess forms, advise the patient to discard the milk if it is pus-like. Flucloxacillin is usually the treatment of choice. It is safe for the baby. Incision and drainage of abscess with cavity packed open with gauze is recommended if the underlying skin is thin or necrotic.

If the patient has mastitis, we would still encourage the patient to breastfeed as the blocked milk ducts may clear more quickly by breastfeeding as it keeps milk flowing. However, if the patient has an abscess, in some cases, breastfeeding may have to cease until the abscess is successfully treated.

This stem should ring bells of neutropenic sepsis. The question deliberately left out the count for neutrophils. This is usually reported together with the white cell counts as it is part of the request for a full blood count. Nonetheless, the white cell count is shown to be low here which is consistent with neutropenic sepsis.

Neutropenic sepsis should not be taken lightly. They can deteriorate rapidly and become hypotensive within hours. If the patient has received chemotherapy within the last 4 weeks and is now having a fever and feeling unwell, he should immediately be started on intravenous broad-spectrum antibiotics. This should ideally be started even before the results of the full blood count come back.

Please see Q- 12

Continue inpatient empiric antibiotic therapy in all patients who have unresponsive fever unless an alternative cause of fever is likely. It is quite the norm to add on IV antifungals for neutropenic sepsis as well. If there was an option to order investigations for fungal infections in this question, that would be correct as well.

General Management for Neutropenic Sepsis :

• Antibiotics must be started immediately (do not wait for the WBC)

• Start empirical antibiotic therapy with piperacillin with tazobactam (Tazocin) immediately

• If the patient is still febrile and unwell after 48 hours, an alternative antibiotic such as meropenem is often prescribed +/- vancomycin

• If the patient is not responding after 4-6 days order investigations for fungal infections, rather than just starting antifungal therapy blindly.

Dengue is characterized by an abrupt onset of fever often accompanied by severe headache and retro-orbital pain, myalgia, arthralgia, nausea, vomiting, and abdominal pain Retro-orbital pain is a well-recognized feature of dengue fever.

A jejunal biopsy shows deposition of macrophages in the lamina propria-containing granules which stain positive for Periodic Acid-Schiff (PAS) and are diagnostic for Whipple’s disease.

Whipple’s disease is a rare disease featuring GI malabsorption which usually occurs in middle-aged white males. It is fatal if untreated and is caused by Tropheryma whipped, which, combined with defective cell-mediated immunity, produces a systemic disease.

Features:

• Often starts insidiously with arthralgia (mainly peripheral joints)

• GI symptoms commonly include colicky abdominal pain, weight loss, steatorrhea/diarrhoea, which leads to malabsorption.

• Systemic symptoms such as chronic cough, fever, sweats, lymphadenopathy, and skin hyperpigmentation also occur

• Cardiac involvement may lead to endocarditis

• CNS features include reversible dementia, ophthalmoplegia, and facial myoclonus.

• Diagnosis requires a high level of clinical suspicion

• Jejunal biopsy shows stunted villi. There is deposition of macrophages in the lamina propria-containing granules which stain positive for Periodic Acid-Schiff (PAS).

This is a very interesting question with a huge debate between Malaria and Schistosomiasis. Initially, one may pick Schistosomiasis as Schistosomiasis is widely distributed in Sudan. 5 weeks here fits the timeline of schistosomiasis as symptoms usually take from four to six weeks from the time of infection.

They may feel generally unwell at this point however in the majority of cases blood in the urine only occurs somewhere between 10 to 12 weeks after the infection. The blood in urine is due to the worms of Schistosoma haematobium migrating to the veins around the bladder and ureters.

In short, a patient suffering from urinary schistosomiasis (caused by Schistosoma haematobium) will develop terminal haematuria, while another patient infected with Schistosoma mansoni may develop hepatomegaly but ultimately these symptoms are caused by different species. Considering the clinical features, the best answer is Malaria.

Blackwater fever is a complication of malaria infection in which red blood cells burst in the bloodstream (hemolysis), releasing hemoglobin directly into the blood vessels and the urine. This accounts for the dark urine. Malaria is also known to cause hepatomegaly.

Please see Q-18

If the patient has received a full five-dose course of tetanus vaccine at the recommended intervals or is up-to-date with their tetanus immunization schedule, no further doses of vaccine are recommended even with a tetanus-prone wound however, high-risk wounds still need intramuscular human tetanus immunoglobulins.

There are some exceptions when tetanus boosters are indicated for patients who have completed their five-dose course of tetanus vaccines but are traveling to remote areas, but this is unlikely to be asked during the exam.

The probable diagnosis here given the symptoms of numerous painful ulcers is genital herpes which is caused by HSV type 2. The two distractors here are Treponema pallidum and Varicella-zoster virus.

Treponema pallidum which causes syphilis presents with PAINLESS papules that later forms PAINLESS ulcers.

Varicella-zoster causes shingles if reactivation occurs later in life which presents with vesiculation and ulceration in a dermatomal distribution.

Post-exposure prophylaxis (PEP) should always be given for 28 days. Serological testing immediately is appropriate as a baseline test.

Drugs used in PEP are a combination of oral antiretrovirals to be given as soon as possible for 28 days. This reduces the risk of contracting HIV.

A very straightforward question. The child is septic with the likely diagnosis of meningococcal septicaemia. Blood culture is the investigation of choice.

The diagnosis here is genital herpes. The pain caused by genital herpes is so severe that it can cause urinary retention. Genital herpes is treated with acyclovir.

Please see Q-10

The most infectious period is 1-2 days before the rash appears, but infectivity continues until all the lesions are dry and have crusted over (usually about 5 days after the onset of the rash). Therefore, children with chickenpox should be kept away from school or nursery until all the vesicles have crusted over.

Please see Q-40

This injury is to be considered a high-risk wound. Intramuscular human tetanus immunoglobulin needs to be administered. Antibiotics would also be useful to add here to prevent wound infection.

Current Hepatitis C virus infection is the correct answer given that the serology is indicative of likely resolved hepatitis B infection as well as the presence of HCV RNA. The histopathological findings in this case are helpful to you if you can remember this from your early days in medical school, however, the serology is enough to get the answer. So don’t be thrown by details like this. Given that the patient is an intravenous drug user, you should consider blood-borne viruses.

Remember hepatitis C is associated with cirrhosis and eventual hepatocellular carcinoma.

Past Cytomegalovirus infection is not correct as there is no indication in the stem or the results that this infection is present. Current Human Immunodeficiency Virus infection is not correct as there is no indication in the stem regarding HIV infection although it is a blood-borne virus. Therefore it is there to try to confuse you.

Previous Hepatitis E virus infection is not the correct answer as there is no mention of hepatitis E virus in the results and this is usually transmitted via faecal-oral route in less developed countries. There is no indication of this in the question.

Current Hepatitis B virus infection is not the correct answer as the blood test results show an equivocal test result which is commonly due to resolved infection.

This is very probable in this case as this is a blood-borne infection and this patient has a major risk factor for contracting this in her life. A relatively low proportion of people with hepatitis B progress to chronic infection.

The patient is immunocompromised. She is on chemotherapy AND she is taking long-term steroids. She is at a high risk of developing severe complications from varicella infection. As she is currently asymptomatic, the best management would be immunoglobulins. If she had developed the infection, then we would administer aciclovir.

This patient is suffering from oral thrush which is also known as oral candidiasis. It is an infection caused by a yeast germ called Candida albicans. This patient has quite a few risk factors for oral thrush. Firstly, he is an elderly man who is diabetic and thus, immunocompromised. He also had a recent course of antibiotics which also contributes to the susceptibility of getting oral thrush.

The clincher to diagnose oral candidiasis in this patient is his positive examination findings. The patches generally progress to form larger plaques and the presence of candida may become painful and cause discomfort in eating food.

The most appropriate treatment option for this patient is an oral fluconazole suspension.

It helps to clear fungal infections in people with a poor immune response who develop extensive oral thrush.

Chlorhexidine mouthwash is an antibacterial mouthwash. It is mainly used to treat gingivitis and is used for the maintenance of oral hygiene. So, that is not the correct option.

It is important to remember the risk factors of tuberculosis as well as how it presents. Weight loss is common because of the chronicity of the infection. Night sweats also occur with TB. Homeless people are at higher risk of TB as they often live in overcrowded areas and have poor housing which encourages the spread of TB. It is estimated that the homeless are 150 times more at risk of TB.

Stain for Acid-Fast Bacilli (AFB) is the most appropriate next test.

Mantoux test and interferon-gamma test are used to diagnose latent tuberculosis infection and not acute cases of tuberculosis.

Bronchoscopy is sometimes used when there is a need to obtain bronchoalveolar lavage or lymph node samples. It is used if a patient has a non-productive cough or an unhelpful sputum culture but the physicians still have a high index of clinical suspicion for tuberculosis.

Please see Q-30

In a hospital setting, give intravenous third-generation cephalosporin antibiotics.

If these same questions were given but she presented them to her GP (or was found outside the hospital), then benzylpenicillin IM or IV would be the correct answer.

If you suspect meningitis and the patient is not yet in the hospital give IM/IV benzylpenicillin and send the patient to the hospital.

If this same question was given, but there was a diagnosis of Listeria, then IV amoxicillin and gentamicin would be the correct answer.

If this same question was given, but she is penicillin or cephalosporin allergic, then chloramphenicol would be the answer.

Generally, treatment for meningitis should be started before doing any investigations due to the seriousness of the disease.

If the patient has a rash, then perform a blood culture as the diagnosis is most likely meningococcal septicemia. The causative organism is Neisseria meningitides.

History of travel to India with grey membrane in tonsil and uvula, and a low-grade fever, supports the diagnosis of diphtheria.

Note that the pseudomembrane may cause respiratory obstruction as seen in this question.

The skin lesions seen in different stages are quite classic for chicken pox. As this man has a temperature of 39.1°C, there is likely a secondary infection that requires oral antibiotics.

Usually, cases of chicken pox only require symptomatic treatment but if chicken pox blisters become infected with bacteria, they would require antibiotic treatment. With a temperature of 39.1°C, oral antibiotics is more suitable than topical.

She has signs of meningitis. Intravenous Ceftriaxone needs to be administered immediately.

One of the delayed complications of meningitis is decreased hearing, or deafness. Hearing loss may be partial or total. People who have had meningitis will usually have a hearing test after a few weeks to check for any problems.

This man has had a painless ulcer (chancre) which healed. This is the primary stage of syphilis.

The reason the stem included that he is homosexual is that syphilis is more common in men who have sex with men.

If syphilis is suspected, blood for VDRL, TPHA, or treponemal antibody absorption should be sent. These are serology tests.

Polymerase chain reaction (PCR) or dark field microscopy can only be carried out from a sample of the lesion or an infected lymph node. Since the ulcer is healed, a sample cannot be obtained. If there was an ulcer visible, a dark field microscopy would allow a point-of-care syphilis diagnosis.

One of the very serious but rare complications of otitis media is meningitis. This patient has clear signs that resemble meningitis.

This patient is immunocompromised. The management for immunocompromised patients exposed to chicken pox differs greatly.

Some physicians may consider offering oral aciclovir to the immunocompromised when exposure is significant.

People who have had a significant exposure to chickenpox and who are immunocompromised should be tested for varicella zoster antibody, regardless of their history of chickenpox. 

The diagnosis of tuberculosis is usually made in one of three ways:

1. Smear of sputum - Staining with Ziehl-Neelsen (ZN) stain and microscopy for acid-fast bacilli

2. Culture of sputum - Takes 4-8 weeks due to slow bacterial growth

3. Histology with caseating granulomas on biopsy

This young child is unable to cough up sputum and thus there is no sample to perform a stain for Acid-Fast Bacilli (AFB).

Bronchoalveolar lavage would be the next step to attempt to acquire a sample given the high index of suspicion for tuberculosis.

As the parents of the child have declined this procedure, gastric lavage would be able to acquire a sample. Some patients with tuberculosis do not raise any sputum but instead swallow small amounts of sputum. 

Basic first aid for needle stick injuries includes washing with soap under running water and encouraging bleeding in that area. When there is a needle stick injury to health care professionals, occupational health must be contacted. The patient should be informed that there has been a needle stick injury and permission should be asked before taking blood for HIV antibodies, hepatitis B surface antigen, and hepatitis C virus antibodies.

Genital warts are benign epithelial skin tumors commonly seen as cauliflower-like growths. They are most commonly caused by HPV types 6 and 11. Transmission is through sexual intercourse. The incubation period is between 3 weeks to several months.

Gardasil is a quadrivalent vaccine that protects against 4 types of HPV: 6, 11, 16, and 18.

HPV 6 and 11 are responsible for benign genital warts, and HPV 16 and 18 are responsible for most cervical cancers. Gardasil does not treat established genital warts.

Treatment options include podophyllotoxin, imiquimod, and ablative methods such as cryotherapy and excision under local anesthetic.

Its recommended to use co-trimoxazole as pneumocystis carinii pneumonia.

Prophylactic treatment of choice for HIV-seropositive patients with persistent CD4 counts less than 200 cells/mm3. Azithromycin has a role in prophylaxis against Mycobacterium avium complex in patients with HIV. It is used when CD4 counts fall below 50 cells/mm3.

Universal prevention application protocol.

Centripetal distribution of blisters favours chickenpox. Adults more commonly develop a more generalized brain inflammation ("encephalitis") whose symptoms may include delirium and seizures. The incubation period of chicken pox is 10-21 days. So this travel history is not significant.

Itchy scaly annular rash after a walk in the park indicates erythema migrans caused by the spirochete Borrelia Burgdorferi transmitted by bite of pinhead-sized Ixodes ticks leading to Lyme disease.

Shuffner dots inside RBC indicate, it is plasmodium ovale or plasmodium vivex infestation. Eradication of the disease needs eradication of the liver cycle. Only primaquine is the drug that can eradicate the hepatic or liver cycle.

The wound is a tetanus prone wound. Here the man has received an adequate priming course of the tetanus vaccine but the last dose was taken more than 10 years ago. So he should take an immediate reinforcing dose of vaccine.

Cough, fever, and cervical lymphadenopathy following travel to India makes the likely diagnosis of TB. Also caseating granulomata are diagnostic of TB.

Infection toxicity or toxic shock syndrome is likely here as preceding flue like illness points towards current staphylococcal pneumonia which resulted release of enterotoxin type B leading to infection toxicity.

Chronic cough and sputum, night sweats and weight loss are classic features of tuberculosis.

Diphtheria is a serious infection caused by strains of bacteria called Corynebacterium diphtheriae that make toxins (poison). History of travel to India, grey membrane in tonsil and uvula, low-grade fever, and dyspnoea suggest the diagnosis of diphtheria.

If the eye is involved, or if immunocompromized, the treatment option is pyrimethamine + sulfadiazine.

Bladder involvement is caused by Schistosoma hematobium while Schistosoma mansoni causes intestinal disease.

Nontreponemal antibody test if positive indicates that there may be syphilis and it is not confirmatory alone.

That is why a treponemal antibody test should also be done to confirm it. On the other hand resolved disease may show a negative treponemal test which is confirmed by a positive non-treponemal test.

Described rash is erythema migrans which is a characteristic skin lesion seen in Lyme disease.

Lyme disease is caused by the bacteria Borrelia burgdorferi which is spread by ticks. The most common sign of infection is an expanding area of redness on the skin, known as erythema migrans, that appears at the site of the tick bite about a week after it occurred. Lyme disease is treated with Doxycycline.

If judicial antibiotics fail to control fever next step is to add antifungal agents.

Cervical lymphadenopathy mentioned in question which occurs in EBV infection.

In Acute retroviral syndrome or primary HIV infection, there is generalized lymphadenopathy.

Infectious mononucleosis, or mono, refers to a group of symptoms such as fever, sore throat, swollen lymph glands in the neck and armpits, headache, fatigue, muscle weakness, swollen tonsils, night sweats usually caused by the Epstein-Barr virus (EBV). It typically occurs in teenagers, but you can get it at any age. The virus is spread through saliva, which is why some people call it “the kissing disease.”

Holiday in Sudan, hematuria, fever and hepatomegaly suggest Schistosomiasis.

Mainly airborne but some cases may occur in close contacts.

If you are pregnant, come into contact with chickenpox case, found antibody negative on blood test you have to take injection Ig. 

A case of chickenpox. None of the given treatments is used in chickenpox. Symptomatic treatments like acetaminophen if fever, antihistamine, and calamine lotions are given.

The incubation period of malaria is 7 - 30 days. Malaria prophylaxis cannot give confirmed protection and there is often failure of prophylaxis.

Fever, vomiting, and neck stiffness are consistent with cerebral malaria. In meningococcal disease, there may be a rash. However meningococcal meningitis may be without rash. But Ghana is the endemic zone for malaria. So cerebral malaria is a stronger probability.

Cough, wt. loss, non-tender cervical lymphadenopathy, and the immunodeficient state as a result of recreational drug use all these favours the diagnosis of TB. Laryngeal involvement may be the cause of horseness.

Spreading annular rash suggests erythema migrans of Lyme disease.

Fever, arthralgia, myalgia, and headache are common in dengue fever. Particularly retro-orbital pain is well well-recognized feature of dengue fever.

Herpes simplex virus causes multiple painful vesicles and syphilis ulcer is painless. As here single painful ulcer probable diagnosis is Chancroid caused by Hemophilus ducreyi.

Sputum can not be obtained in extremes of age as in too young or elderly. When initial dry cough of TB sputum may not be coughed up by patients as well.

So in such cases bronchoalveolar lavage (BAL) can demonstrate the bacteria. If BAL is refused alternate other procedures such as gastric washing can be done.

When a patient coughs the saliva is contaminated with coughed-up droplets and swallowed by the patient. So gastric lavage can bring these organisms with samples of gastric washing.

Cough, fever, night sweats, and weight loss in a homeless lady are very suggestive of TB. So we should do AFB as her next investigation.

Central caseous necrosis with surrounded fibrosis is diagnostic of TB lymphadenitis. The most common cellular components seen are epithelioid cell clusters, lymphocytes, and Langhans giant cells.

Mumps is a viral disease caused by the mumps virus. Initial symptoms are non-specific and include fever, headache, malaise, muscle pain, and loss of appetite. These symptoms are usually followed by painful swelling of the parotid glands, called parotitis, which is the most common symptom of infection.

Cough, night sweats, and weight loss are common features of TB. Apical lesions in the lung on chest X-ray are suggestive of PTB (pulmonary tuberculosis). The most discriminating investigation is AFB for sputum.

“NEXT” best step is clean the wound.

Dengue fever

This type of question can be regarded as cns infection in AIDS and some may argue there is no mention of AIDS. If you consider with immunocompetent patient likely answer may be HSV and if you consider immunodeficiency likely answer is controversial! as some say toxoplasmosis is the most common and some say Cryptococcus is the most common.

Cardiac complications of Lyme disease generally occur in the early phase and include conduction system disturbances, myopericarditis and congestive heart failure.

Low-grade fever, night sweats, anorexia, dry (initially) or productive cough, and upper lobe cavitary lesions are highly suggestive of TB.

Coxsackie virus

Chicken pox is centripetal infection where rashes are predominant on trunk and face and less in extremities. There are lesions of different stages. In children herpes zoster is unlikely and chicken pox is common.

Shuffners dot indicates either vivax or ovale infection and the hepatic cycle only can be eradicated by primaquine.

Intermittent fever is seen in malaria. In meningitis, fever is not intermittent. Also, Sudan is endemic for malaria.

Hepatitis B

To exclude any spinal cord pathology.

The symptoms and arrival from an endemic area for Pulmonary TB suggest the best course of action would be to go for AFB staining via ZN stain.

Though in infectious mononucleosis lymph nodes are usually seen in a posterior triangle but can be seen in the whole body including the anterior triangle also.

IV acyclovir

Orchitis

Mumps

Doxycycline

Diagnosis is Atopy (allergy).

Diagnosis is hereditary angioedema. Acquired angioedema usually manifests after the age of 40 yrs.

Urticaria

Oral antihistamine

Allergic reaction

Anaphylaxis with partially blocked airway.

In anaphylaxis adrenaline 0.5ml of 1:1000 is given IM whereas in cardiac arrest 1 ml of 1:1000.

Patient is getting anaphylactic shock with the difficulty of breathing and slurred speech (probably from tongue swelling) which is an indication of IM adrenaline.

Allergic reaction

It is a spindle-cell tumour derived from capillary endothelial cells or from fibrous tissue, caused by human herpes virus. It presents as purple papules (½ to 1 cm) or plaques on skin and mucosa (any organ). It metastasizes to nodes.

Fever, dry cough, breathlessness, tachypnoea with clear chest is seen in pneumocystis carinii pneumonia. Normal oxygen saturation which drops on exercise is characteristic of pneumocystis carinii pneumonia.

The lesion described is leukoplakia which is likely association of HIV disease.

Though not mentioned IV drug abusers may have tricuspid regurgitation causing pan systolic murmur and HIV is also very common in this group.

Weight loss in a homosexual is likely to be due to AIDS and CMV retinopathy with retinal hemorrhage is a recognized association.

IV drug abuser, weight loss, breathlessness and dry cough with interstitial shadowing indicate PCP pneumonia in an AIDS patient.

In IVDA immunity becomes low and easily gets infected with TB.

NHL is more likely diagnosis in AIDS or immunodeficient state.

Blood transfusion is the clue for HIV transmission. Immunodeficiency is also responsible for TB.

In AIDS patients common cause of diarrhea is cryptosporidium.

Case of HIV. Cryptococcus can cause meningitis in AIDS patients