Dermatology Oasis

Editor: Nameer Al-Sudany, MD (IRAQ)

Pityriasis versicolor


Pityriasis versicolor is a summarizing and memorizing name !!!
* Cause: Overgrowth of Pityrosporum orbiculare (a lipophilic commensal yeast).
* Lipophilic yeast means:
A. Occurs around and after puberty (rare in children): Androgen activation of sebaceous glands (Sebum).
B. Favors seborrheic areas particularly the upper trunk.
C. Can’t be isolated in culture (Sabouraud’s agar) medium without adding an oily material (Olive oil).
* Versicolor means it presents with different colors, namely: hyperpigmented, pinkish red or hypopigmented.
* Pityriasis: means the rash is covered with fine powdery bran-like scales.
* The scaly nature of the rash can be exaggerated by stretching the skin between 2 fingers (an important clue to diagnosis).
* Pale or golden yellow under wood’s lamp examination.
* Characteristic spaghetti and meat-ball appearance of the mycelium under KOH smear examination.