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 l esions influences the disease processes of AD. Objective We describe the importance of the presence of S. aureus and staph ylococcal 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 SEE in the eczematous skin o f AD using immunofluorescence, the effects of SEA and SEB on normal human e pidermal keratinocytes in organ culture, and the presence of specific IgE a ntibodies 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 d ermal-infiltrated cells, especially on eosinophils. SEA and SEB stimulated expression of ICAM-1 and HLA-DR in normal human keratinocytes. More than ha lf of the AD patients in the present study had specific IgE antibodies to S EA and/or SEB in their serum. Conclusion S. aureus and SEs have important roles in the exacerbation and p rolongation of AD.