What is the recommended treatment for a pediatric patient with a fingernail issue, such as paronychia or a fungal infection?

Treatment of Pediatric Fingernail Issues

For pediatric fingernail fungal infections (onychomycosis), oral terbinafine is the first-line treatment at 62.5 mg daily for children <20 kg for 6 weeks, while acute bacterial paronychia requires warm soaks, topical antiseptics, and drainage if an abscess is present. 1, 2, 3

Diagnostic Confirmation is Essential

Never treat based on appearance alone—laboratory confirmation is mandatory before initiating antifungal therapy. 4, 1

• Direct microscopy with potassium hydroxide (KOH) preparation and fungal culture on Sabouraud's glucose agar are essential for confirming fungal infection 1
• Calcofluor white staining enhances visualization of fungal elements 1
• 50% of nail dystrophy cases are non-fungal despite similar clinical presentation, making empiric treatment inappropriate 4, 1
• Examine family members for onychomycosis and tinea pedis, as household transmission is common 1, 2
• Check for concomitant tinea capitis and tinea pedis in the child 1

Treatment Algorithm for Confirmed Fungal Infection

First-Line Systemic Therapy

Oral terbinafine is preferred over itraconazole for dermatophyte onychomycosis in children. 2

• Dosing by weight: 62.5 mg/day if <20 kg, 125 mg/day for 20-40 kg, 250 mg/day if >40 kg 1, 2
• Duration: 6 weeks for fingernails, 12 weeks for toenails 1, 2
• Monitoring: Baseline liver function tests and complete blood count are recommended 2
• Common adverse effects: Headache, taste disturbance, gastrointestinal upset 2
• Efficacy: 88% cure rate, with children responding better and faster than adults 1, 2

Alternative First-Line: Pulse Itraconazole

Use pulse itraconazole when terbinafine is contraindicated or for Candida species infections. 1, 2

• Dosing: 5 mg/kg/day for 1 week per month 1, 2
• Duration: 2 pulses (months) for fingernails, 3 pulses for toenails 1, 2
• Efficacy: 94-100% clinical cure rates for confirmed fungal infection 1
• Azoles are specifically advocated when onychomycosis is caused by Candida species 1

Second-Line Options

• Fluconazole: 3-6 mg/kg once weekly for 12-16 weeks (fingernails) or 18-26 weeks (toenails) if terbinafine and itraconazole are contraindicated 2
• Griseofulvin: 10 mg/kg/day, but not recommended as first-line due to long treatment duration (at least 4 months for fingernails) and low efficacy 2, 5

Topical Therapy Considerations

Topical therapy may be more effective in children than adults due to thinner, faster-growing nails. 2

• Amorolfine 5% lacquer or ciclopirox 8% lacquer can be used 2, 6
• Combination of topical and systemic therapy may provide antimicrobial synergy and improved efficacy 2
• Topical therapy alone is generally insufficient for established infections 6

Treatment Algorithm for Bacterial Paronychia

Acute Paronychia Management

Warm soaks with or without Burow solution or 1% acetic acid are first-line for acute paronychia without abscess. 3

• Keep the affected area dry and apply topical povidone iodine 2% twice daily 1
• Topical antibiotics with or without topical steroids when simple soaks do not relieve inflammation 3
• Abscess requires drainage: Options range from instrumentation with hypodermic needle to wide incision with scalpel 3
• Oral antibiotics usually not needed if adequate drainage is achieved unless immunocompromised or severe infection present 3

Pathogen Considerations in Pediatrics

Children with oral self-soothing behaviors (thumb sucking, finger sucking) have mixed anaerobic and aerobic infections, not just Staphylococcus aureus. 4, 7, 3

• Chronic paronychia in children is often related to thumb sucking, causing cuticle detachment and secondary infection 4
• Initial therapy with broad-spectrum antibiotics (amoxicillin/clavulanate or clindamycin) is suggested for pediatric paronychia 7
• Pseudomonas aeruginosa causes Green Nail Syndrome (green or black discoloration), treated with ciprofloxacin 1, 6

Chronic Paronychia

Chronic paronychia (≥6 weeks duration) is an irritant dermatitis requiring removal of the irritant source and topical steroids or calcineurin inhibitors. 3

• This is frequently non-infective but may become secondarily colonized by fungi 8
• Treatment may take weeks to months 3
• Dermatology consultation should be obtained for suspected chronic paronychia 8

Prevention of Recurrence

Preventing reinfection requires environmental and behavioral modifications. 2

• Apply antifungal powders (miconazole, clotrimazole, or tolnaftate) to shoes and feet 2
• Wear cotton, absorbent socks and keep nails short 2
• Avoid sharing nail clippers with family members 2
• Consider disinfecting or discarding contaminated footwear 2
• General hygiene measures and concomitant use of appropriate topical agents are usually required 5

Critical Pitfalls to Avoid

• Do not assume fungal infection without laboratory confirmation—50% of dystrophic nails are non-fungal 4, 1
• Do not overlook examination of family members for fungal infections, as household transmission is common 1, 2
• Do not continue medication indefinitely—clinical relapse occurs if medication is not continued until the infecting organism is completely eradicated 5
• Do not ignore underlying conditions—consider psoriasis, lichen planus, trauma, and yellow nail syndrome in the differential 1
• Do not use topical therapy alone for established fungal infections affecting >50% of nail plate or >3 nails 6