Pityriasis Versicolor Flashcards
Pityriasis versicolor or tinea versicolor is a superficial infection of the skin caused by
Malassezia furfur (Pityrosporum orbiculare).
Malassezia furfur (Pityrosporum orbiculare) requires
fatty acids for growth, hence is cultured on the Sabouraud’s dextrose agar (SDA) overlayed with a layer of olive oil.
On incubation at 37°C
the fungus produces creamy colonies within 5–7 days
The lactophenol cotton blue (LPCB) wet mount of these colonies shows
budding yeast cell along with a number of bottle-shaped cells
The fungus is found in
parts of the body rich in sebaceous glands
The lesions of pityriasis versicolor are found most commonly on
the upper tissue, arms, and abdomen
They appear as
hypopigmented macular lesions often associated with slight scaling or itching
The condition is
mostly asymptomatic
It occurs most frequently in
hot and humid weather.
Laboratory diagnosis of the condition is usually made by
demonstration of both budding yeast cell and hyphae in KOH preparation of skin scrapings
What is demonstrated in the microscopy of KOH preparation of the skin
Characteristic “spaghetti and meatballs” appearance of fungus is demonstrated
Culture is not
carried out routinely for diagnosis
Treatment
Topical miconazole is treatment of choice.
