[Malassezia folliculitis: characteristics and therapeutic response in 26 patients]

Malassezia folliculitis is most often described in patients living in hot and humid countries or in immunocompromised patients. Its frequency in France is unknown. We report 26 cases diagnosed at Saint-Louis Hospital between May 2002 and April 2004. The clinical features, the contributing factors, the results of direct mycological examination and/or histology and the efficacy of antifungal treatments were compared to the literature.

The inclusion criteria were the presence of folliculitis on the trunk confirmed by direct microscopy and/or histopathology showing abundant yeast cells in the follicles.

Patients comprised 22 men and 4 women (M/F sex ratio: 5: 5) with a mean age of 46 years. Five patients (19%) were immunocompromised. In normal patients, the duration of folliculitis was long with a mean of 61 months. The eruption was typical, with follicular papules and superficial pustules distributed predominantly on the trunk. Itching was frequent (70%). Direct microscopy was more often positive than histology (89% vs 33%). Some sixty-five percent of the patients had been previously treated by topical or systemic antibiotics or anti-acne drugs, which was ineffective in all cases. Cure with topical ketoconazole, oral ketoconazole alone or in combination with topical ketoconazole occurred respectively in 12%, 75% and 75% of patients, but with consistent recurrence within 3 to 4 months after cessation of treatment.

Malassezia folliculitis is probably misdiagnosed, as suggested by the long time between onset and diagnosis and the high frequency of non-antifungal treatments prescribed. In our study, direct mycological examination provided more effective diagnosis than histology. Treatment is difficult especially because of the high frequency of relapses.

A diagnosis of Malassezia folliculitis should be considered in young adults or immunocompromised patients with an itching follicular eruption. Further therapeutic trials are needed due to the frequency of relapse.