Childhood white superficial onychomycosis caused by Trichophyton rubrum: Report of seven cases and review of the literature

Background: Although white superficial onychomycosis (WSO) is well recognized in adults and considered to be mainly caused by Trichophyton mentagrophytes, childhood WSO is rare. WSO caused by Trichophyton rubrum in prepubertal children has never been reported. Objective: Our purpose was to describe the existence of WSO in children and to emphasize that T. rubrum may be its main cause. Methods: Seven children with WSO seen between 1988 and 1993 were examined. Only patients who had a positive potassium hydroxide preparation and a positive fungal culture were included. Results: Seven healthy prepubertal children, 2 to 9 years of age, were identified with WSO. All cases were proved to be caused by T. rubrum. Six patients had associated tinea pedis, and five had a family history of tinea pedis. Topical antifungal therapy was partially effective in some cases. Conclusion: This report documents the existence of WSO in prepubertal children. All cultures grew T. rubrum. Although onychomycosis is not as common in prepubertal children as in adults, it may be underrecognized.