The Pathogenic Role of Microbes in Seborrheic Dermatitis

To the Editor.—  The review of skin infections in the immunocompromised host in a recent issue of the Archives¹ omitted what is probably the most common example of that occurrence, ie, the frequent appearance of seborrheic dermatitis in patients with the acquired immunodeficiency syndrome (AIDS).² Despite the objections that have been expressed about the role of microbes in the pathogenesis of seborrheic dermatitis,³ there is now over-whelming evidence in favor of microbes playing a pathogenic role,^4-8 and a recent reviewer has declared the argument ended.⁹ In our own experience, AIDS-related seborrheic dermatitis is associated with large numbers of Malassezia organisms on affected sites and responds rapidly to treatment with 2% ketoconazole cream, thus providing further evidence of a microbial origin.¹⁰