Exacerbation of atopic dermatitis by staphylococcal colonization

Keiji Iwatsuki, Takashi Oono, Osamu Yamasaki

Research output: Contribution to journalArticlepeer-review

Abstract

Staphylococcus colonization is one of the aggravating factors in patients with atopic dermatitis. The Th2 inflammatory response and persistent IL-18 secretion from keratinocytes is induced by wall TA and protein A, respectively. Staphylococcus enterotoxins A (SEA) and B (SEB) stimulate the expression of ICAM-1 and HLA-DR in normal human keratinocytes, and more than half of patients with atopic dermatitis have specific IgE antibodies to SEA and/or SEB in their serum. Epicutaneous sensitization with SEB elicites a local, cutaneous inflammatory response characterized by dermal infiltration with eosinophils and mononuclear cells, and induces mRNA expression of the Th2 cytokine, IL4 without increased expression of the Th1 cytokine, IFN-γ. Epicutaneous exposure to superantigens skews the immune response toward Th2, leading to allergic skin inflammation and increased IgE synthesis. Patients with atopic dermatitis have significantly increased numbers of regulatory T (Treg) cells with normal immunosuppressive activity. However, after superantigen stimulation, Treg cells lose their immunosuppressive activity. S. aureus, therefore, may aggravate atopic dermatitis by immunomudulatory effects of the cell components and exotoxins. Neither antimicrobial nor antiseptic treatment is effective for eradication of colonizing S. aureus in the horny layers covered with biofilm.

Original languageEnglish
Pages (from-to)29-32
Number of pages4
JournalSkin Research
Volume5
Issue numberSUPPL. 7
Publication statusPublished - Nov 1 2006
Externally publishedYes

Keywords

  • Antimicrobial treatment
  • Atopic dermatitis
  • Biofilm
  • Colonization
  • S. aureus
  • Th2

ASJC Scopus subject areas

  • Dermatology
  • Infectious Diseases

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