During the summer months three young patients were examined by us for an asymptomatic cutaneous eruption of erythematous papules located on neck, shoulders and back. They were heat-resistant to several antiseptics and systemic antibiotic treatment. The mechanical expression of these lesions did not reveal the appearance of pus, but a hard keratinous matter. The histopathological findings of the lesions show a non specific folliculitis, but the PAS stain shows numerous spores of yeast forms within the keratinous material of the follicle. The culture of this material in bacteriological and mycological ordinary media is negative, but the culture in the Dixon media reveals the growth of typical colonies of Pityrosporum orbiculare. The patients responded successfully to a 3 weeks course of ketoconazole (200 mgr/d).