A 25-year-old man returns from a gap-year in Central and South America and presents with a 2 month history of an ulcerating lesion on his lower lip. Examination of his nasal and oral mucosae reveals widespread involvement.
What is the likely cause?
Correct Answer A: Mucocutaneous ulceration following travel? - Leishmania brasiliensis.
This patient most likely has leishmaniasis. The pattern of a primary skin lesion with mucosal involvement is characteristic of Leishmania brasiliensis.
Leishmaniasis:
Leishmaniasis is caused by the intracellular protozoa Leishmania, usually being spread by sand flies. Cutaneous, mucocutaneous leishmaniasis and visceral forms are seen.
Cutaneous leishmaniasis:
Mucocutaneous leishmaniasis:
Visceral leishmaniasis (kala-azar):
*occasionally patients may report increased appetite with paradoxical weight loss.
A 33-year-old man who is HIV positive is admitted to the Emergency Department with confusion and drowsiness. A CT head shows multiple ring enhancing lesions.
What is the most likely diagnosis?
Correct Answer C: HIV - multiple ring enhancing lesions = toxoplasmosis.
Cerebral toxoplasmosis is the most common neurological infection seen in HIV, occurring in up to 10% of patients. HIV neurocomplications:
1- Generalised neurological disease: Encephalitis:
Cryptococcus:
Progressive multifocal leukoencephalopathy (PML):
AIDS dementia complex:
2- Focal neurological lesions:
Toxoplasmosis:
Primary CNS lymphoma:
Differentiating between toxoplasmosis and lymphoma is a common clinical scenario in HIV patients. It is clearly important given the vastly different treatment strategies. The table below gives some general differences. Please see the Radiopaedia link for more details.
Tuberculosis:
A 30-year-old man is diagnosed as having malaria following a recent trip to Zimbabwe.
Which one of the following is most likely to indicate severe malaria?
Correct Answer E: A respiratory rate of 30 per minute may indicate acute respiratory distress syndrome (ARDS), a feared complication of falciparum malaria. Whilst thrombocytopaenia can be caused by disseminated intravascular coagulation (DIC), it is also seen in many patients with uncomplicated malaria and hence would not automatically indicate severe malaria.
Malaria: Falciparum: Feature of severe malaria:
Complications:
Uncomplicated falciparum malaria:
Severe falciparum malaria:
A 30-year-old intravenous drug user is diagnosed as having osteomyelitis of the right tibia.
What is the most likely causative organism?
Correct Answer C:
Osteomyelitis: Osteomyelitis describes an infection of the bone. Staph. aureus is the most common cause except in patients with sickle-cell anaemia where Salmonella species predominate.
Predisposing conditions:
Investigations:
Management:
A 30-year-old woman presents with a white, malodorous vaginal discharge. There is no associated itch or dyspareunia. A diagnosis of bacterial vaginosis is suspected.
Overgrowth of which one of the following organisms is most likely to cause this presentation?
Correct Answer E: Bacterial vaginosis - overgrowth of predominately Gardnerella vaginalis.
Bacterial vaginosis: Bacterial vaginosis (BV) describes an overgrowth of predominately anaerobic organisms such as Gardnerella vaginalis. This leads to a consequent fall in lactic acid producing aerobic lactobacilli resulting in a raised vaginal pH. Whilst BV is not a sexually transmitted infection it is seen almost exclusively in sexually active women.
Features:
Amsel's criteria for diagnosis of BV - 3 of the following 4 points should be present:
Bacterial vaginosis in pregnancy:
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