Association of hypersensitivity and carriage of dermatophytes in clinically normal sites in patients with Tinea cruris.

Forty nine patients with mycologically confirmed Tinea cruris were investigated for the association of hypersensitivity to trichophytin and the isolation of dermatophytes from clinically normal sites with chronicity and recurrence of infection. At the end of six months following specific therapy, 24 patients returned for follow up and they were similarly studied. Dermatophytes were isolated from clinically asymptomatic sites in 46% patients before treatment and in 21% of the patients on follow up. Immediate weal reaction and increased concentration of IgE antibodies were seen in 73% and 80% of the patients respectively. However, the delayed hypersensitivity reaction was more associated with patients having lesions for more than 6 months (48%) in comparison with patients with a short history (17%). On follow up after 6 months, the different hypersensitivity reactions and IgE antibody concentration maintained more or less the same association. Therefore in persistent or recurrent Tinea cruris infection, besides potential carriage in clinically normal sites, hypersensitivity to antigens of dermatophytes possibly plays an important role in pathogenicity.