Case-based Review of Microbiology Flashcards
A patient with PMH notable for AIDS presents with headache, nausea, vomitting, and confusion over the last few days. Upon examinaton they have a staggered gait and exhibit right sided ptosis. They describe that they are careful to avoid exposure to potential infection, and that the only regular routine they have outside of the house is going to feed the pidgeons on weekday mornings.
The following image is obtained from CSF staining.
Diagnosis: Cryptococcosis
Organism: Cryptococcus neoformans
Diagnostic technique: India ink staining of CSF
Treatment: Amphotericin B + flucytosine (combined treatment)
A patient presents to dermatology clinic concerned that they may be developing vitiligo. They point to a patch of skin that is hypo-pigmented, the borders of which are defined because they went sun tanning recently. You apply Wood’s lamp and the patch is not enhanced. A picture is provided.
Diagnosis: Pityriasis versicolor
Organism: Malassezia furfur
Diagnostic technique: Potassium hydroxide preparation (‘spaghetti and meatballs’ appearance’
Treatment: Topical imidazole or selenium sulfide-containing shampoo
A patient presents to dermatology clinic concerned that they have developed a melanoma. It appeared acutely on the sole of their palm.
Diagnosis: Tinea nigra
Organism: Exophiala werneckii
Diagnostic technique: Potassium hydroxide preparation - brown pigmented, branched, septate hyphae and budding yeast
Treatment: Topical imidazole or selenium sulfide-containing shampoo
