Oral antihistamine therapy influences plasma tryptase levels in adult atopic dermatitis.

Background: Atopic dermatitis (AD) is an allergic skin disease that follows a clinical course of 'flare-up' and remission. Histamine and tryptase are inducers of pruritus and non-sedating second-generation antihistamines, including fexofenadine, are widely used for treatment of allergic skin disorders.

Objective: We assessed the efficacy of a second-generation antihistamine in AD patients and examined its pharmacological effects on chemical mediators.

Flow cytometric analysis of IL-4, IL-13 and IFN-gamma expression in peripheral blood mononuclear cells and detection of circulating IL-13 in patients with atopic dermatitis provide evidence for the involvement of type 2 cytokines in the disease.

Recent studies have shown increased T-helper (Th) 2 cytokine expression and decreased IFN-gamma expression in peripheral blood from patients with atopic dermatitis (AD). In the present study, we examined the cytokine expression in peripheral blood mononuclear cells in patients with AD and tested how the cytokine profile correlated with the patients' age, severity and laboratory findings. Peripheral blood mononuclear cells obtained from 20 patients with AD were stimulated with phorbol 12-myristate 13-acetate and ionomycin, and were examined for the frequencies of CD4+ cells expressing IL-4, IL-13 and IFN-gamma at the single cell level using intracellular cytokine staining and flow cytometry.