Pityriasis versicolor

What it is

Pityriasis versicolor, also called tinea versicolor, is a common superficial cutaneous fungal infection. It is caused by Malassezia furfur, formerly termed Pityrosporum ovale, and the point to hold on to is that Malassezia is not a dermatophyte. It is common in hot, humid climates, and it is not contagious.

Malassezia furfur is the name to hold, and Pityrosporum ovale is its former name.

Malassezia furfur, formerly known as Pityrosporum ovale, is a normal skin inhabitant. The same fungus is met again in seborrhoeic dermatitis, which is thought to be caused by an inflammatory reaction related to a proliferation of that normal skin inhabitant - so the name is met twice, and the two are told apart by the lesions and where they sit, not by the fungus.

Causes and risk

It occurs in healthy individuals, so an otherwise well person is the usual host. The predisposing factors listed alongside that are immunosuppression, malnutrition and Cushing's.