Pityrosporum folliculitis is a common kind disorder in young or middle-aged adults that involves follicular papules and pustules localized predominantly on the back and chest. As the name suggests, it is caused by the invasion of the hair follicle by Malassezia yeasts. Although Malassezia yeasts are a part of the normal human microflora, under certain conditions they can cause superficial dermatological conditions. The invasion results in the development of erythematous papules, and sometimes pustules, which may be either asymptomatic or itchy. Usually pityrosporum folliculitis is present along with staphylococci and propionibacteria in the follicles.

The Pityrosporum folliculitis infection is lipophilic (requiring the presence of lipid substances for their development, in either skin sebum or culture media) yeasts commonly found on skin and body surfaces of humans and animals. There are seven proposed species in the genus Malassezia based on molecular, morphological, and biochemical profiles. Their variable morphology and the difficulty in isolating and maintaining them in culture have brought about a long-lasting controversy on the role of the Malassezia yeasts in various skin conditions. During the past two decades, this group of yeasts has gained increasing importance, and great progress has been made in defining the ecology and implicit role of the different species in associated pathological disorders.

Malassezia yeasts are classified as superficial mycoses that, by definition, do not invade past the cornified epithelium. In Pityrosporum folliculitis, however, the organism is present in the osteum and central and deep segments of the hair follicle. All the species have distinct morphological characteristics, which allow them to be differentiated from other yeasts. The cells are round, oval or cylindrical, depending on the species. The reproduction of Malassezia is asexual with unipolar budding, the daughter cells being formed successively in a single locus, leaving a prominent scar on the mother cell. Some species may develop pseudomycelium in vivo as well as in vitro.

With regards to the Pityrosporum folliculitis, Malassezia yeasts require free fatty acids to survive. The yeasts hydrolyze triglycerides into free fatty acids and create long-chain and medium-chain fatty acids from free fatty acids, resulting in a cell-mediated response, which leads to inflammation. Because of their dependence on lipids for survival, Malassezia yeasts are found in sebum rich areas of the body such as the trunk, back, face and scalp.

The pathogenic agents identified in Pityrosporum folliculitis are yeasts from the genus Pityrosporum–Pityrosporum orbiculare and Pityrosporum ovale, which are collectively known as Malassezia furfur. It is not clear whether the organism plays a pro-active causative role or whether there is merely a proliferation of Malassezia in the enlarged follicle. However, direct microscopy and histopathology show that there is a definite and clear pattern of colonization of hair follicles by Malassezia yeasts. The role of Malassezia yeast in pityrosporum folliculitis is further endorsed by the fact that topical antifungal treatment is effective in most cases.

Most infectious diseases seen by dermatologists and clinicians can be successfully managed if the true etiology of the patients’ dermatosis is known. After that, it is a simple process of therapeutic follow up that ensures resolution of the problem. Pityrosporum folliculitis has a tendency to happen again; treatment must be two-pronged. Therapy must be directed both at restraining yeast overgrowth as well as tackling predisposing factors, to avoid recurrence.

Specific treatment for pityrosporum folliculitis can be divided into Topical treatment and Oral treatment. Topical treatment includes antidandruff shampoo as a cleanser and Topical antifungal agents, especially ketoconazole or ciclopirox creams or econazole foaming solution. For the oral treatment, Azole antifungal agents including ketoconazole, fluconazole and itraconazole can be used in the treatment of pityrosporum folliculitis.