Katsutaro Nisimoto: Tinea Pedis -- An Opportunistic Infection

Background: Onychomycosis is a very common and widespread disorder, however the incidence of onychomycosis in psoriatic patients is not accurately assessed. Objective: The present study was undertaken to evaluate the frequency of fungal infections of the nails changed in the course of psoriasis and to provide an answer whether psoriatic nails are specially predisposed to fungal infections. Material and Methods: 83 psoriatic patients with nail changes participated in the study. Among them there were 25 females and 58 males, aged 18~76 years. 59 patients (71.1%) had psoriasis vulgaris, the remaining ones 24 subjects (28.9%) suffered from arthropathic psoriasis. In any case of nail abnormalities clinically suspected of fungal infection the further mycological investigations were performed. Fungal infections were finally diagnosed on the base of direct microscopy and positive culture. The Chi test and the Mann-Whitney U-test were used for statistical analysis. Results: Positive mycological cultures were obtained from 15 patients (18%). The most commonly isolated fungi were moulds cultured in 6 patients (37%), followed by dermatophytes 5 patients (31.5%) and yeast-like fungi also 5 subjects (31.4%). Moulds and yeast-like fungi were found in both fingernails and toenails; all dermatophyte infections were diagnosed on the toenails. Psoriatic patients with fungal nail infections were older than those with negative mycological examination and the duration of psoriasis in this group of patients was also longer. Although the above differences between two studied groups were evident, they did not reach the statistical significance. Conclusions: Based on the achieved results it is difficult to assess definitely whether psoriasis is a predisposing factor to the development of fungal infections of the nails. [Kor J Med Mycol 2003; 8(2): 43-47]