An Open-Label, Proof of Concept Study to Determine the Safety and Efficacy of Ketoconazole 2% Foam in the Treatment of Pityrosporum Folliculitis

Malassezia/pityrosporum species is a ubiquitous saprophyte of human skin. This organism is implicated in the etiology of seborrheic dermatitis, tinea versicolor, and pityrosporum folliculitis. The prevalence of pityrosporum folliculitis is especially high in warm and humid environments, although its presence is universal. Pityrosporum folliculitis presents in immuno-competent, acne-prone young adults as fine superficial follicular pustules and papules on the trunk and upper extremities. There are no comedones. This acneiform condition is non-scarring. It causes significant morbidity for patients as it is frequently mistaken for acne vulgaris with scarring potential, often associated with pruritis, and fails to respond to adequate conventional acne treatment- systemic antibiotics, topical benzoyl peroxide, and topical retinoids. Pityrosporum folliculitis can be the sole presenting condition or it can coexist with acne vulgaris. Less commonly, patients with pityrosporum folliculitis present with associated tinea versicolor and seborrheic dermatitis. The diagnosis is made by clinical presentation, microscopic examination for the pustule for spores/hyphae, skin biopsy, and retrospectively following good response to antimycotic therapy. Ketoconazole 2% foam was recently approved for the treatment of seborrheic dermatitis in immunocompetent patients 12 years and older. Safety and efficacy of ketoconazole 2% foam treatment for pityrosporum folliculitis has not been established. Prior to the availability of the ketoconazole 2% foam, successful treatment of pityrosporum folliculitis required systemic anti fungal drugs such as ketoconazole, itraconazole and fluconazole. It also responds to oral isotretinoin. Systemic antimycotics are effective but repeated use of these drugs incurs safety concerns including hepatotoxicity and drug-drug interactions. Oral isotretinoin is indicated for severe nodulo-cystic acne and generally is inappropriate as a routine treatment modality for pityrosporum folliculitis. As pityrosporum folliculitis is a non-scarring acneiform condition and can be recurrent, effective and safe, patient initiated topical treatment would be a more appropriate form of therapy.The objective of this study is to demonstrate that ketoconazole 2% foam may be the treatment of choice for pityrosporum folliculitis.