Onychomycosis in Children with Down Syndrome

Fungal infection of the nail, known as onychomycosis, occurs more frequently in older age, showing a higher prevalence in pediatric age in recent years. A high rate of dermatological infections befalls in patients with Down syndrome, including onychomycosis, due to a decrease in T and B lymphocytes in number and function, resulting in a disarrangement of cellular and humoral immunity. This has led to several investigations on onychomycosis in children with Down syndrome, so the purpose of this review is to show the available evidence.

The etiological agents of onychomycosis can be dermatophytes, non-dermatophyte molds, and yeasts. Most cases are related with dermatophytes; Trichophyton rubrum being the most common cause. In children with Down syndrome, T. rubrum has been reported as the main cause, followed by T. mentagrophytes. Distal lateral subungual onychomycosis is the most common variety of onychomycosis in children. The importance of identifying the fungus lies in selecting the appropriate treatment, since not all antifungals have the same spectrum of action against molds and Candida. Terbinafine has showed to be safe and effective for the treatment of onychomycosis in patients from special populations, including children with Down syndrome. In patients with Down syndrome, treatment for onychomycosis has not been completely studied; so far, terbinafine has shown the best results.

The clinical presentations of children with Down syndrome and the rest of the general pediatric population are similar. However, there are few studies about onychomycosis in children with Down syndrome. It is necessary to perform new onychomycosis research in this study population, in order to establish recommendations.