Malassezia: a case of coexisting pityriasis versicolor and Malassezia folliculitis

摘要

In the human fungal biodata, Malassezia is the dominant species. It is a skin commensal that has been implicated in diseases such aspityriasis versicolor (PV), Malassezia folliculitis (MF), seborrhoeic dermatitis, atopic dermatitis and psoriasis.(1) Environmental factorssuch as increased temperature, sweating, seborrhoea,(2) and immunosuppressive conditions such as human immunodeficiency virus(HIV) infections, diabetes mellitus and corticosteroid use are associated with a predisposition to the development of PV and MF.(3)A 24-year-old Chinese man was referred to the dermatology clinic for an asymptomatic rash on his back, arms, thighs andbuttocks of two months’ duration. The patient had a past medical history of Evan’s syndrome (autoimmune thrombocytopenia andhaemolytic anaemia), for which he was on long-term azathioprine and prednisolone for immunosuppression. He was otherwisewell and had no constitutional symptoms. On examination of the affected areas, there was a monomorphic erythematous pustulareruption with multiple annular scaly hypopigmented macules and patches within (Fig. 1). A fungal scrape from lesional areas waspositive for hyphae and spores.