Clinical and mycological study of occult tinea pedis and tinea unguium in dermatological patients from Tokyo.

An epidemiological investigation was conducted to determine the prevalence and circumstances of untreated, unsuspected tinea pedis and tinea unguium, morbid conditions that could be termed occult athlete's foot, in patients visiting a dermatology clinic in Tokyo, Japan, for the first time, for other complaints. All subjects completed a questionnaire covering comprehensive anamnestic details, and were examined for disposition of toes, presence of signs suggestive of tinea pedis, other diseases of the foot, score of clinical signs and symptoms, potassium hydroxide (KOH) test, severity score, and mycological culture. The results showed that the prevalence of occult athlete's foot was 25%, and that 59% of those cases were complicated by tinea unguium. The characteristics of patients with occult athlete's foot included a higher proportion of men and a tendency toward a low clinical score together with a high severity score. In the patient background, a strong correlation was observed between a positive KOH test result and characteristics such as age, disposition of toes, and predisposing disease.