Does Pityrosporum Ovale Have a Role in Psoriasis?

To the Editor.— A patient with psoriasis developed guttate lesions in areas of pityrosporum folliculitis. Report of a Case.— An 11-year-old Hispanic girl with Down syndrome was admitted for treatment of severe psoriasis; she was in otherwise good health. There was a 4- to 5-year history of generalized psoriasis involving 90% of her cutaneous surface. During admission, a modified Goerckerman regimen, including topical steroids, tar, and UVB light, was instituted resulting in initial improvement. However, the course of therapy was complicated by an eruption of dozens of follicular pustules on the trunk and proximal extremities (Fig 1). Gram's stain revealed numerous polymorphonuclear cells, but no organisms; orally administered erythromycin therapy was begun for the presumptive diagnosis of a bacterial folliculitis. However, many pustules became surrounded with guttate psoriasis. A biopsy of a pustule revealed folliculitis with inflammatory infiltrate and pityrosporum organisms in the yeast state; the spores were within the