Isotretinoin may sometimes be an effective alternative or adjunctive treatment. Pityrosporum folliculitis is another infectious folliculitis that presumably is caused by a host reaction to the yeast Malassezia furfur , previously named Pityrosporum ovale , a normal human skin commensal. It appears primarily on the trunk and upper extremities of late adolescents and young adults. Unlike acne vulgaris, it is pruritic, does not contain comedones, and responds to appropriate antifungal therapy rather than antibiotics. The yeast and hyphae can be seen in biopsy specimens in the widened follicular ostia along with keratinous material, and, occasionally rupture of the follicular wall may occur.
Treatment typically involves topical or systemic antifungal therapy.
Histopathology reveals a predominantly perifollicular infiltration of eosinophils with some mononuclear cells and subcorneal pustules composed of eosinophils. Patients also may demonstrate blood eosinophilia and leukocytosis. Treatment modalities and results vary greatly. Other infectious diseases also may induce an acnelike pattern. In secondary syphilis, papulopustules and nodules, some crusted, may occur on the face, trunk, and extremities.