An immunohistochemical analysis of cytokine expression in allergic and irritant contact dermatitis

The purpose of this study was to investigate whether the specific and non-specific inflammatory responses to allergens and irritants give rise to immuno-histochemical detectable differences in the cytokine profile in the skin. Skin biopsies taken at 0, 6, 24 and 72 h from contact allergic reactions to nickel and from irritant reactions to sodium lauryl sulphate were analysed. The main finding was that the dermal cells expressed similar patterns of cytokines (IL-1alpha, IL-1beta, IL-2, IL-4, IL-6 and IL-10) in both types of contact reaction at 72 h. However, two differences were observed. Staining for the IL-1 receptor antagonist was more prominent in the dermis at the late stages of the allergic reaction compared with the late stage of the irritant reaction. The other difference was an increased interferon-gamma staining of infiltrating mononuclear inflammatory cells in the dermis in the sodium lauryl sulphate group compared with the nickel group. A more rapid general onset of cytokine production was found in the sodium lauryl sulphate group than in the nickel group. The main conclusion of this study was that after 6 h the cytokine patterns did not differ between the specific and the non-specific inflammatory responses in the skin.