Dermatology phrase..what is pityrosporum?

Pityrosporum folliculitis is a condition where the yeast, pityrosporum, gets down into the hair follicles and multiplies, setting up an itchy, acne-like eruption. Pityrosporum folliculitis sometimes turns out to be the reason a case of acne isn't getting better after being on antibiotics for months. It is especially common in the cape distribution (upper chest, upper back) and the pimples are pinhead sized and uniform.

It is a genus of fungi that includes one species that can cause tinea versicolor (an eruption of tan or brown patches on the skin) and another that is found primarily on the face and scalp and appears in dandruff and seborrheic dermatitis (a chronic form of dermatitis characterized by oily scales, crusty yellow patches, and itching, and occurring primarily on the scalp and face. Hope this helps some.