Dermatology Online Journal

Onychomycosis in children
Nadine Lateur
Abstracts of the Fifth Meeting of the European Nail Society: DOJ 9(1): 17E

CHU Saint Pierre, Brugmann and HUDERF - Free University of Brussels, Brussels, Belgium

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A retrospective study of our laboratory findings over a ten-year period, provided us with some useful information. Four and a half percent (963) of the samples taken from patients consulting us for a nail problem belonged to children. In 296 (30.74%) of these children, laboratory examination confirmed the diagnosis of onychomycosis.

The number of cases rose quickly with the age of the child, only ¼ being below the age of 6. In these small children, toenails were already frequently involved. In this group, yeasts were slightly more frequently isolated from culture than dermatophytes:. although as the majority of cases were secondary infection rather than true onychomycosis, Trichophyton (T.) rubrum may already be considered as the main pathogen. In the group above the age of six, toenail is the main location, and T. rubrum the main pathogen. Candida albicans and T. mentagrophytes variety interdigitale are rarely involved. Mould onychomycosis is not restricted to the elderly: a 7-year-old girl had a Scopulariopsis sp. infection.Similarly to adults, distal and lateral onychomycosis is the main clinical form. In 3 children, both finger- and toenails were infected. Based on our culture results, we are convinced that although sports attendance is an important risk factor, swimming pool attendance plays a minor role. Indeed in the Brussels' swimming pools, T. interdigitale is the main encountered dermatophyte, but onychomycosis due to T. interdigitale could only be found in 9 of the children.

In immunocompetent small children, topical treatment should be considered first. Imidazoles can be used under occlusion, which enhances their penetration. Although not much has been published about their use in children, nail lacquers (amorolfine, ciclopirox) could be a useful alternative, providing that the nail is not sucked by the child.

Among systemic antifungals, fluconazole, itraconazole and terbinafine are safe and efficient in children. Terbinafine is mainly active against dermatophytes, and its daily dosage is dependant on the child's weight: 62.5mg if its weight is below 20kg, 125mg between 20-40kg, and 250mg above 40kg. Duration of therapy, as in adults, is 6 weeks for a fingernail and 12 weeks for a toenail.

Itraconazole has a broad spectrum but must be taken with a meal. Again dosages are related to the child's weight: 5mg/kg/d under 20kg, 100mg/d between 20-40kg, and 200mg/d above 40kg. As in adults, it can be given continuously for 6-12 weeks, according to the location of the infection, or as a pulse therapy.

Fluconazole must be given until cure is achieved, but does not need to be taken with food. It is very interesting for congenital and neonatal candidiasis, where it is given intravenously. The child should receive 6mg/kg on the fjirst day, 3mg/kg on the second day and then, with a frequency of 3mg/kg every 3, 2 or 1 day intervals depending the newborn's age. In chronic mucocutaneous candidiasis, the dosage is 6-12mg/kg/d. In countries where its liquid formulation is available, it could be useful in treating a small child's onychomycosis at a dosage up to 9mg/kg/week.

References

Elewski BE. Onychomycosis: Pathogenesis, Diagnosis and Management. Clin Microbiol Rev 1998; 11(3): 415-429

Gupta AK et al. Onychomycosis in children: Prevalence and treatment strategies. J Am Acad Dermatol 1997; 36: 395-402

Caputo et al. Prevalence of superficial fungal infections among sports-active individuals: results of the Achilles survey, a review of the literature. J Eur Acad Dermatol 2001; 15: 312-6

Detandt M, Nolard N. Fungal contamination of the floors of the swimming pools, particularly subtropical swimming paradises. Mycoses 1995; 38: 509-13

Lateur N, Mortaki A, André J. 296 cases of onychomycosis in children and teenagers: a ten-year laboratory survey. Pediatr Dermatol (accepted for publication)

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