Staphylococcus aureus in the lesions of atopic dermatitis

Quantitative aerobic cultures were obtained from fifty patients with chronic plaques, and from twenty with exudative lesions of atopic dermatitis. In the former, Staphylococcus aureus was isolated from 90% and the density exceeded 1 × 106/cm2 in 45% of the samples. In the exudative form, Staph. aureus was recovered in every case with a mean density of 14 × 106 organisms per cm2. Staph. aureus was the dominant organism not only in the lesions but in nearby clinically normal skin. Despite these high numbers, clinical signs of infection were lacking. Systemic and topical antibiotic therapy pro‐duced a profound decrease in Staph. aureus density. It is proposed that high numbers of Staph. aureus may aggravate the underlying lesion and be the source of Staph. aureus infections in contacts.