BACKGROUND The association of dermatophytes with atopic patients and improvement in allergic signs with antifungal treatment suggest a possible link between chronic infection and atopy. OBJECTIVE The purpose of this study was to determine skin reactivity and serum IgE antibody responses in patients with chronic and acute dermatophytosis. METHODS One hundred and sixty-three patients with chronic dermatophytosis, 35 patients with acute dermatophytosis, 41 atopic patients and 49 healthy subjects were enrolled in this study. Sensitization to Trichophyton mentagrophytes (T. mentagrophytes), Candida albicans and Aspergillus fumigatus antigens has been evaluated in patients by skin prick test (SPT) and by the presence of specific IgE antibody in enzyme-linked immuno-sorbent assay (ELISA). RESULTS Positive immediate hypersensitivity (IH) reactions were obtained in 95.1% of the atopic patients with chronic infection for T. mentagrophytes, representing a significant difference from other patient groups (P < 0.05). Specificanti-T. mentagrophytes IgE antibodies were detected in atopic patients with chronic (65.9%) and acute (50%) dermatophytosis, while none of the atopic subjects had positive IgE reactions to T. mentagrophytes. CONCLUSIONS The results showed significant higher positive IH and specific anti-T. mentagrophytes IgE responses in atopic patients with chronic dermatophytosis than the other groups.