Staphylococcal toxins in patients with psoriasis, atopic dermatitis, and erythroderma, and in healthy control subjects.

Background: The aggravating role of Staphylococcus aureus superantigens is well known in atopic dermatitis (AD) but has not yet been proven in psoriasis (PS).
Objective: We investigated the distribution of S aureus in the skin and nares of patients with AD, PS vulgaris, erythroderma, skin infections, and sepsis, and in healthy control subjects. A Staphylococcal enterotoxin test-reversed passive latex agglutination (SET-RPLAR) test was performed to determine Staphylococcal enterotoxins A, B, C, and D.
Results: S aureus was cultivated from lesional skin of 22 of 25 patients with AD and 15 of 25 patients with PS. Isolated strains were toxigenic in 44% for patients with AD and in 36% for patients with PS. The activity of disease in AD and PS according to the Severity Scoring of Atopic Dermatitis (SCORAD) or Psoriasis Area and Severity Index score, respectively, correlated significantly (P = .001) with an isolated toxigenic strain in both diseases. S aureus from skin infections was toxigenic in half of the patients. All patients with erythroderma harbored S aureus, mostly on their skin. In AD, sepsis and skin infections, toxin C and in PS toxin B was most often detected. S aureus was cultured in 12% of healthy persons. These strains were toxin negative. The limitations of these investigations are that other potentially acting enterotoxins, such as toxic shock syndrome toxin-1, which may play a role in aggravating disease, were not investigated with our latex agglutination test.
Conclusion: In this study, S aureus was present in more than 50% of patients with AD and PS. We found that the severity of AD and PS significantly correlated to enterotoxin production of the isolated S aureus strains.