mycology cases Flashcards
Patient presents complaining of strange black granules on his scalp. They are hard “concretions”. What is the bug and how do you test for it?
Black Piedra: Piedrae Hortae
Superficial fungus, wet prep KOH10%
While completing a physical for a man, you notice soft, white granules in his beard, connected to his hairs not scalp. What is the bug and how do you test for it?
White Piedra: Trichospora Beigelli
Superficial fungus, can also be found on pubic hairs. KOH10%
Child is brought to your office with strange discolorations on the palms and soles. Brown black macules are noted. What is the bug and how do you test for it?
Tinea Negra: Exophilia Wernickii
Superficial fungus, KOH10%
A woman presents complaining of strange discolorations on her torso. Upon examination you see diffuse, scaly hyper and hypopigmentation. What is the bug and how do you test for it?
Tinea versicolor: Malassezia Furfur
Superficial fungus, KOH10%
Child visits the office with several round, red patches on her skin. Your preceptor asks what three genera of fungus could cause this, and how to test for it.
Ringworm: Tinea corporis
Dermatophyte/ cutaneous fungi may be 1. Microsporum, 2. Trichophyton, 3. Epermophyton. Test for all of these using KOH10% wet prep, or culture in media with cycloheximide/chloramphenicol to inhibit overgrowth of other fungi and bacteria.
A woman who gardens as her hobby enters the acute care clinic complaining of strange nodules on her arm. During the exam, you see she has a splinter in her palm, and the painless nodules are moving away from the site along her lymph drainage. What is the bug, how did she get it, and how to test?
Sporothrix Schenkii: lymphocutaneous sporotrichosis
This dimorphic bug is found in soil, splinters, rose thorns. It enters the subq and travels along the lymph drainage channels. A culture will turn from white mold to black yeast after incubation.
A male patient in Virginia was recently taking apart and old, rotting wooden shed in his backyard. Now, he has warty lesions on his hands which look like cauliflower. What’s the bug, and what color would it be under histology study?
Fonsecae/ Cladosporium: Chromoblastomycosis
this bug lives in rotting wood and soil, enters the sub q by trauma and creates the Cauliflower appearance. This fungus will Copper colored when studied, spherical and may have Medlar bodies. Virginia was only mentioned because this patient is NOT near the Mississipppi river.
Patient has had ongoing purulent drainage from nose and sinuses. Upon exam, you can make out sulfur colored granules in the turbinates, and remove one for culture. What will you find?
Pseudallescheria Boydii or Madurella Arisea
both cause Eumycotic Mycetoma with purulent discharge and sulfur granules in the sinus tracts
An African American man in a desert region of Arizona presents with a chronic cough. His vital signs are normal, and his chest xray is clear. He has seen multiple providers for this, but no one has found cause. Given the location, which type of fungus might be responsible? How would you test?
Coccidoides Immitis, primary lung infection
This deep tissue fungus is unique because: it is found in southwest US deserts, is actually symptomatic in 40% of patients (most are not), and tends to target individuals who are pregnant, hiv positive, or have dark skin.
Culture sputum, biopsy to rule out cancer, “complement fixation” test
An HIV positive woman living on the Mississippi river presents with general flu like symptoms and chest discomfort. She says she’s worried about TB, but because of where she lives you’re worried about a fungus. What bug are you going to test for, and what long term effect concerns you?
Histoplasmo Capsulatum: deep tissue fungus
This fungus is located primarily along the Mississippi river where bats and birds defecate into the soil. Usually asymptomatic, but in HIV patients it can become disseminated through the blood and effect every part of the body. Disseminated H. Capsulatum is called Histoplasmosis and it is fatal. A Giemsa stain will show phagocytized yeast inside monocytes.
A woman recently returned from Brazil with a fever and cough. A sputum test shows a strange Mariner’s wheel organism. What is the bug?
Paracoccidioides Brasiliens
Central and south American dimorphic fungus with a google worthy shape of a Mariner’s wheel- like a pirate ship’s wheel. It wasn’t discussed, but this particular form of deep tissue fungus can cause GI, skin and mucosal issues that are pretty serious.
An adult male on long term antibiotics for acne comes to your office with a scrapable white covering on his tongue. What caused it, how do you test, and why did it happen?
Candida Albicans: thrush
This fungus normally lives on our skin and in our GI Tract, but forms superficial infections of the mouth, esophagus or skin/ nails, and vagina when neutrophils are low in number. Culture or biopsy.
This can become an invasive/ systemic issue in immunocompromised individuals.
A Neutropenic oncology patient presents coughing up blood. On chest xray, you see a fungus ball. What is the bug and how do you test? What is the long term threat of this specific fungus’ toxins?
Aspergillus: aspergilloma
Low neutrophil patients can have aspergilla in the lungs as an opportunistic infection, presenting as a fungus ball in an old cavity of the lung and creating severe hemoptysis. It can also cause allergic reaction symptoms in some patients. It can also be a systemic illness of eyes, bones, sinuses etc
Aspergilla releases AflaToxins = liver cancer
Aspergilla likes blood vessels = thrombosis and infarcts
Culture biopsy
A diabetic patient is brought to the ER with acidosis after being noncompliant with his insulin therapy for several months. He is treated, but still complains of severe facial pain. Upon exam, his sinuses are tender on palpation. If bacteria is ruled out, which fungus might be the problem?
Zygomycetes: Zygomycosis
Opportunistic infection of uncontrolled diabetics, burn patients, Neutropenic patients. It can cause pneumonia, sinus/skin infections. Culture and biopsy.
An AIDs patient has nuchal rigidity, high fever, productive cough and looks very toxic. What fungus are you concerned about and how do you want to test for it?
Cryptococcus
Affects t-cell deficient patients causing pneumonia, meningitis, and can be systemic to skin/prostate. 10% of all AIDS patients have this. It’s also common in people who use long term steroids or have lymphoma. Caused by pigeon excrement and “debris under the gum tree”.
Culture CSF, Urine, blood, sputum.
India ink is a good stain.
