Malassezia (Pityrosporum) Folliculitis

Updated: Oct 07, 2024
  • Author: Sarah Sweeney Pinney, MD, FAAD; Chief Editor: William D James, MD  more...
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Overview

Practice Essentials

Malassezia (Pityrosporum) folliculitis (MF) is an inflammatory skin disorder that typically manifests as a pruritic, follicular papulopustular eruption distributed on the upper trunk of young to middle-aged adults. Pityrosporum folliculitis was first described by Weary et al in 1969, and it was identified as a separate clinical and histologic diagnosis by Potter et al in 1973.

Yeasts, Malassezia furfur in particular, are the pathogens in MF. M furfur has been linked to several skin diseases, including seborrheic dermatitis, folliculitis, confluent and reticulated papillomatosis, and pityriasis versicolor. [1, 2, 3]  In 1874, Malassez described round and oval budding yeasts from scales of patients with seborrheic dermatitis, using the phrases "bottle bacillus of Unna" for the small oval cells in the scale and "spore of Malassez" for the bud associated with the yeast. In 1904, Saborouraud proposed the genus Pityrosporum for the budding yeast cells without hyphal elements from normal skin. Later in the 1900s, the species Pityrosporum ovale and Pityrosporum orbiculare were isolated.

As a consequence of controversy and confusion regarding the grouping of various lipophilic yeasts and fungi of the skin, these two yeast species, collectively with fungal forms, were reclassified under a single name, M furfur,which applies regardless of the morphology of the organism.

 
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