Candida albicans, applied to human skin under occlusion for 24 hours, induced a pustular dermatitis, the severity of which was proportional to the size of the inoculum. The 105cells produced infections in 95% of the patients. Blacks were more resistant than whites, thoughCandidagrew well. Mycelial forms were rare and were not a prerequisite for a take. Infections were readily induced on skin that was stripped to the glistening layer, casting doubt on the importance of anti-Candidaserum factors. In atopic and psoriatic skin, infections only occurred when the existing microflora was eradicated.Candida albicansis not a secondary invader in dermatitic skin.