A 15-year-old male came to clinic because of his left great toenail had become yellowish and thicker over the last 1-2 months. He played multiple sports and had tinea pedis during basketball season 3-4 months earlier, but had noticed this during the spring baseball season. He denied any erythema, burning, itching or pain in his feet or nails. He had no changes to his hands. “I’ve been changing my socks more often, using shower shoes in the locker room and airing out my feet at home, but now I have this,” he commented. The past medical history was non-contributory. The family history was negative for dermatological problems with the exception of atopic dermatitis in one sister.
The pertinent physical exam showed a healthy male with normal vital signs and weight in the 50% and height in the 90%. His dermatological examination was negative including his hands with the exception of his left great toe with showed hyperkeratotic, easily friable nail with yellowish coloration. There was no erythema, drainage, pain or other problems with the nail, along with no signs of other affected nail or tinea pedis. The diagnosis of onychomycosis was made. A culture was sent which eventually grew Trichophyton rubrum. He was treated with intraconazole daily for 12 weeks. He appeared to have clinical resolution at this time. His nailbed returned to normal by 9 months.
Onycomycosis is a fungal infection of the nails. It has a world-wide prevalence of 0.3% with some geographical variations such as in the U.S. it is 0.44%. It is an uncommon problem especially in children. It is very uncommon in those under 6 years and only very sporadic case reports in those under 2 years. The lower incidence is felt to be due to children’s faster nail growth, smaller surface to infect, reduced exposure to fungi, lower prevalence of tinea pedis and especially less cumulative trauma. Onycomycosis is more common in families (unsure if this is due to genetic factors or family members having more onycomycosis and therefore increased environmental exposure), people with immunodeficiencies (especially adult diabetic patients or HIV), and people with Down’s syndrome. Trauma is a major predisposing factor as is hyperhidrosis.
Clinical presentation includes color changes of the nail plate (often yellowish), debris under the nail bed, hyperkeratosis and thickening of the nail, and onycholysis.
Family members should also be checked for onycomycosis and tinea pedis.
Distal and lateral subungual onycomycosis is the most common. Dermatophytes especially are the usual cause especially Trichophyton rubrum but other causes include Candida sp. and nondermatophyte species such as Aspergillus.
Onycomycosis is difficult to treat and can recur. Systemic medications (often prolonged) are often the mainstay, but topical medications are also being used more. Because onycomycosis is uncommon in the pediatric age groups, clinical treatment studies very limited.
A 2017 review article found 7 studies with the sample size from 1-40 patients (5 studies had only 8 or fewer patients enrolled). In the largest study of 40 patients, a control or ciclopirox nail lacquer was applied daily for 32 weeks. At 32 weeks, 34.2% were cured. At one year, 12 patients were available to be evaluated and 11 of the 12 were cured. During the study, 2 patients using the vehicle also had cure, which the authors believe may be due to “…weekly removal of lacquer and mechanical trimming….”
A 2018 review of treatment agents in children found “…antifungal therapies used to treat onychomycosis in children are associated with a low incidence of adverse events. Current dosing regimens for antifungal drugs are effective and appear safe to use in children….” The weighted average cure rates were highest for intraconazole (oral), terbinafine (oral) and ciclopirox (topical). Cure rates depend on definition (i.e. clinical cure and/or myocological cure.
Other topical treatments include amorolfine, bifonazole, terbinafine, ketoconazole, efinazonazole and tavaborole. Systemic medications frequently include intraconazole, terbinafine, griseofulvin and fluconazole.
Questions for Further Discussion
1. What are some potential side effects of systemic oral treatment for onychomycosis?
2. What causes white nails (leukonychia)? For a review, click here.
3. What does tinea pedis look like?
- Age: Teenager
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.
Information prescriptions for patients can be found at MedlinePlus for these topics: Nail Disease and Fungal Infections.
To view current news articles on this topic check Google News.
To view images related to this topic check Google Images.
To view videos related to this topic check YouTube Videos.
Chadeganipour M, Mohammadi R. Causative Agents of Onychomycosis: A 7-Year Study. J Clin Lab Anal. 2016 Nov;30(6):1013-1020.
Solis-Arias MP, García-Romero MT. Onychomycosis in children. A review. Int J Dermatol. 2017 Feb;56(2):123-130.
Eichenfield LF, Friedlander SF. Pediatric Onychomycosis: The Emerging Role of Topical Therapy. J Drugs Dermatol. 2017 Feb 1;16(2):105-109.
Gupta AK, Mays RR, Versteeg SG, Shear NH, Friedlander SF. Onychomycosis in children: Safety and efficacy of antifungal agents. Pediatr Dermatol. 2018 Sep;35(5):552-559.
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa