Pediatric Onychomycosis: The Emerging Role of Topical Therapy
February 2017 | Volume 16 | Issue 2 | Original Article | 105 | Copyright © February 2017
Lawrence F. Eichenfield MD and Sheila Fallon Friedlander MD
University of California, Rady Children’s Hospital, San Diego, CA
Abstract
Fungal infection of the nails is an increasingly recognized disease in infants and children. However, it can be difficult to distinguish clinically from other nail dystrophies. In addition, many mistakenly believe that onychomycosis does not occur in childhood. Under-recognition of this infectious disorder therefore occurs. Although many consider “nail fungus†a trivial cosmetic concern, it can lead to discomfort, risk of secondary infection, and a more significant health threat in immunocompromised or diabetic individuals. It should always be considered in the differential diagnosis of nail plate disorders in children as it is one of the more common causes.
Here we review the latest data on prevalence of the disease, reasons for its relatively low incidence compared with adults, and important predisposing factors. It is important to confirm the clinical diagnosis of onychomycosis in children, and affected individuals should be examined for concomitant tinea pedis. As familial disease often occurs, it is important to check parents and siblings as well for onychomycosis and tinea pedis.
Treatment of onychomycosis is challenging, and recurrence appears to be more common in children than in adults. Prolonged systemic antifungal therapy is commonly required. However, pediatric practitioners and parents alike hesitate when asked to treat young children with a systemic drug that requires laboratory monitoring and can have systemic toxicities. Due to their thinner, faster-growing nails, children are theoretically more likely to respond to topical monotherapy than adults, and therefore good candidates for topical antifungal therapy.
The clinical data on the use of topical antifungals in pediatric onychomycosis is scarce. We review data that exist from case reports and small clinical trials. New topical antifungals are now available that afford better nail penetration and additional delivery routes to the site of infection. Pediatric trials are now on-going, and should clarify the usefulness of these agents in children.
J Drugs Dermatol. 2017;16(2):105-109.
INTRODUCTION
Onychomycosis in children is considered uncommon; yet it is increasingly seen by pediatric practitioners, is often under-recognized in primary care, and reportedly represents 15.5% of all nail dystrophies in children.1 It may be difficult to distinguish clinically from noninfectious nail dystrophy as a feature of trauma, psoriasis, atopic dermatitis, and alopecia areata.2 Nevertheless, onychomycosis should be considered in differential diagnosis of nail plate disorders in children and even newborns (Table 1).3,4 Prevalence varies depending on age, gender, geography, culture and seasons. Its incidence increases with age5,6 with a worldwide prevalence of 0.3%.7,8 Higher rates are seen in some tropical countries perhaps due to humid conditions that might in uence the presence of tinea pedis. Incidence may be increasing as a result of higher rates of obesity and diabetes seen in children today. Onychomycosis is particularly unusual in children under 6 years.9 In an 18-year study of 408 Icelandic children the incidence of positive dermatophyte culture was found in only eight children aged 0-4 years, and in 57 aged 10-14 years.10 In a ten-year laboratory survey of children with proven onychomycosis in Belgium more than three quarters were older than 6 years, with boys more frequently affected than girls.5 The ratio in favor of male gender seems to be more pronounced in older children (aged 10-18 years).8,11 Some have theorized this could be related to the higher incidence of repetitive traumatic injury to the feet in contact sports such as football and soccer, sports previously favored by adolescent males versus females. No significant gender differences are seen in young children up to one year.12 In North America, a prevalence of 0.44% has been reported.7 A more recent 5-year retrospective chart review of children (aged 13) The lower incidence of onychomycosis seen in children versus adults may be due to faster nail growth, reduced exposure to fungi, smaller nail surface available for fungal invasion, lack of cumulative trauma, and a lower prevalence of tinea pedis.1,7,5,10,14
