Microbial flora of atopic dermatitis.

The microbial flora of dermatitic skin, uninvolved skin, and the anterior nares of subjects with atopic eczema were investigated. The carriage rate of Staphylococcus aureus was 79% for the anterior nares, 76% for the uninvolved skin (normal skin), and 93% for lesions. The counts of S aureus were 7.5 X 10(4)/sq cm in lesions and 7.1 X 10(3)/sq cm on adjacent normal skin. Staphylococcus aureus was the predominant organism in the lesions and constituted 91% of the total aerobic bacterial flora. The coagulase-negative staphylococci were the second predominant organisms (9%). On normal skin, coagulase-negative staphylococci were the predominant organisms, constituting 63% of the total flora, followed by S aureus (30% of the bacterial flora). The micrococci counts were lower in the lesions (1.6 X 10(2)/sq cm) and higher on normal skin (9.5 X 10(2)/sq cm). Lipophilic diphtheroids were fewer on normal skin (6.7 X 10/sq cm), and there were none in the lesions. Fifty-eight percent of the strains belonged to group 3, and 38% were nontypeable. Staphylococcus aureus strains belonging to phage groups 2 and 4 were not detected.