Possible influences of Staphylococcus aureus on atopic dermatitis-- the colonizing features and the effects of staphylococcal enterotoxins.

BACKGROUND: Heavy colonization of atopic dermatitis (AD) with Staphylococcus aureus is well documented. This phenomenon suggests that S. aureus in AD lesions influences the disease processes of AD.

OBJECTIVE: We describe the importance of the presence of S. aureus and staphylococcal enterotoxins A and B (SEA, SEB) in AD lesions.

METHODS: We investigated the colonizing features of S. aureus in AD lesions using electron microscopy, the distribution of SEB in the eczematous skin of AD using immunofluorescence, the effects of SEA and SEB on normal human epidermal keratinocytes in organ culture, and the presence of specific IgE antibodies to SEA and/or SEB in serum of AD patients by enzyme immunoassay.

RESULTS: S. aureus in AD lesions colonized on and in the horny layers of the eczematous skin. SEB produced by S. aureus was distributed mainly on the dermal-infiltrated cells, especially on eosinophils. SEA and SEB stimulated expression of ICAM-1 and HLA-DR in normal human keratinocytes. More than half of the AD patients in the present study had specific IgE antibodies to SEA and/or SEB in their serum.

CONCLUSION: S. aureus and SEs have important roles in the exacerbation and prolongation of AD.