Summertime brings many fun adventures. Unfortunately, it also brings predictable illness and injury (ex, Gastroenteritis, Handlebar Injuries, Sparkler Injuries). People also tend to wear less clothing and that can allow parents to see those areas that have been hidden all winter long. Fingers and Toes are now exposed to the world! Certainly, they are prone to be injured themselves (ex, Subungal Hematoma), but sometimes they just look “funny.” While Onychomycosis is certainly not a medical emergency, its presence may be enough to concern a parent to come to ask you for your advice. So let’s take a quick look at what advice there may be for us to care for the child with Onychomycosis:

Onychomycosis: Basics

Onychomycosis is a fungal infection of the nail plate caused by:
- Dermatophytes (Trichophyton rubrum is the most common cause [Totri, 2017])
- Non-dermatophyte Molds
- Candida

Risk Factors:
- Local nail trauma
- Occlusive foot wear
- Communal locker rooms
- Public swimming pools
- Patient or Family member with tinea pedis [Totri, 2017]
- Down Syndrome
- Immunocompromised patients

Onychomycosis is very common in adults, but Uncommon in children.
- Children have faster nail growth, smaller nail surface area, and lower incidence of nail trauma. [Totri, 2017]
- Prevalence in children ranges from 0.2-2.6% [Totri, 2017]

Onychomycosis: Types

There are several types described. [Chu, 2014]
- Distal Lateral Subungal onychomycosis
- Proximal Subungal onychomycosis
- Superficial White onychomycosis
- Candida onychomycosis
- Endonyx onychomycosis
- Total Dystrophic onychomycosis

Children most often have the Distal Lateral Subungal type. [Chu, 2014]
- Yellow discoloration of nail plate (can be other colors too)
- Subungal debris
- Separation of the nail plate from nail bed (onycholysis)
- Thickening of the distal and lateral aspects of the nail.

Onychomycosis: Mimics

Not every dystrophic or discolored nail has a fungal infection. [Chu, 2014]

Melanocytic lesions
Psoriasis
Lichen planus
Alopecia areata
Atopic dermatitis
Congenital nail dystrophies

Onychomycosis: Management

Diagnosis should be made prior to treatment. [Totri, 2017; Chu, 2014]
- Avoids inappropriately treating a mimic of onychomycosis.
- Avoids unnecessary exposure to prolonged treatment courses with medications that may have substantial side effects.

Diagnostic Tools:
- Fungal Culture
  - Considered the standard since it provides information on pathogen. [Totri, 2017]
  - Nail clippings can be sent in formalin
  - Before obtaining sample, area should be cleaned with alcohol and then nail clipped back to the area of most active infection. [Chu, 2014]
  - (This totally does not sound like something I’m doing in my ED… maybe that is just me…)
- KOH prep and direct microscopy
- PCR is evolving and may prove to be more useful.

Therapies:
- Oral antifungal therapy
  - Currently the widely chosen option. [Chernoff, 2016; Chu, 2014]
  - May require monitoring of CBCs and LFTs, although currently debated. [Chernoff, 2016]
  - Medication inserts recommend checking levels before starting the therapy. [Castelo-Soccio, 2018]
  - Best Options:
    - Oral Intraconazole
    - Oral Terbinafine
    - Griseofulvin and fluconazole are not as effective.
- Topical antifungal therapy
  - May be more effective in children than adults. [Friedlander, 2013]
  - Most useful for Superficial White or mid-moderate Subungal onychomycosis.
  - Avoids systemic treatment, although good results found with using combination of oral and topical antifungal therapies. [Friedlander, 2013]
  - Options:
    - Topical Ciclopirox 8%
    - Topical Amorolfine 5%

Moral of the Morsel

It’s Toe Fungus! Or… is it? Don’t be cavalier and be in a rush to treat a condition that may be a mimic of it instead. It is ok to counsel and recommend outpatient referral for acute diagnostic testing.
Paint it on! Kids do better with topical therapy. While initiating therapy without a diagnosis is not recommended, if you had to, and it was a minor infection, try something topical.

References

Gupta AK1,2, Mays RR1, Versteeg SG1, Shear NH3, Friedlander SF4. Onychomycosis in children: Safety and efficacy of antifungal agents. Pediatr Dermatol. 2018 Jun 26. PMID: 29943838. [PubMed] [Read by QxMD]

Castelo-Soccio LA1,2, Rubin AI1,2,3, Streicher JL1,2. Utility of Baseline Transaminase Monitoring During Systemic Terbinafine Therapy for Pediatric Onychomycosis-Reply. JAMA Dermatol. 2018 May 1;154(5):627. PMID: 29562074. [PubMed] [Read by QxMD]

Solís-Arias MP1, García-Romero MT1. Onychomycosis in children. A review. Int J Dermatol. 2017 Feb;56(2):123-130. PMID: 27612431. [PubMed] [Read by QxMD]

Totri CR1, Feldstein S2, Admani S3, Friedlander SF3,4, Eichenfield LF3,4. Epidemiologic Analysis of Onychomycosis in the San Diego Pediatric Population. Pediatr Dermatol. 2017 Jan;34(1):46-49. PMID: 27699839. [PubMed] [Read by QxMD]

Eichenfield LF, Friedlander SF. Pediatric Onychomycosis: The Emerging Role of Topical Therapy. J Drugs Dermatol. 2017 Feb 1;16(2):105-109. PMID: 28300851. [PubMed] [Read by QxMD]

Chu DH1, Rubin AI2. Diagnosis and management of nail disorders in children. Pediatr Clin North Am. 2014 Apr;61(2):293-308. PMID: 24636647. [PubMed] [Read by QxMD]

Young LS1, Arbuckle HA, Morelli JG. Onychomycosis in the Denver pediatrics population, a retrospective study. Pediatr Dermatol. 2014 Jan-Feb;31(1):106-8. PMID: 22612465. [PubMed] [Read by QxMD]

Friedlander SF1, Chan YC, Chan YH, Eichenfield LF. Onychomycosis does not always require systemic treatment for cure: a trial using topical therapy. Pediatr Dermatol. 2013 May-Jun;30(3):316-22. PMID: 23278851. [PubMed] [Read by QxMD]

Onychomycosis