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Fungal Nail Infection (Onychomycosis)

NICE CKS Fungal nail infection. Last revised: Aug 2023.

Background Information

Causative Agent

  • 85-95% are caused by dermatophyte infections
    • Most common: Trichophyton rubrum
  • 5-10% are caused by Candida species
  • 2-5% of toenail onychomycosis are caused by non-dermatophyte moulds (e.g. ScopulariopsisScytalidiumAspergillusFusarium, and Acremonium species)

Guidelines

Investigation and Diagnosis

Onychomycosis is a clinical diagnosis.

If antifungal treatments are being considered → arrange nail clippings and/or scrapings for fungal microscopy and culture

Management

General Management / Self-Care Advice

Self management:

  • Keep nails trimmed short and filed down
  • Wear well-fitting non-occlusive shoes, without high heels or narrow toes
  • Wear cotton, absorbent socks
  • Maintain good foot hygiene, including prompt treatment of any associated tinea pedis
  • Wear protective footwear when using communal bathing places, locker rooms, and gymnasiums, to avoid re-exposure.
  • Avoid prolonged or frequent exposure to warm, damp conditions if possible
  • Avoid trauma to the nails if possible

Measures to prevent spread and transmission:

  • Avoid sharing toenail clippers
  • Replace old footwear that could be contaminated with fungal spores

Antifungal Treatment

DO NOT routinely offer antifungal to all patients, treatment is only indicated if:

  • Symptomatic (walking is uncomfortable)
  • Psychological distress due to cosmetic appearance

Choice of Antifungal

For early distal and superficial nail involvement: amorolfine 5% nail lacquer

If self-care measures alone and/or topical treatment not successful or appropriate: oral antifungal

Identified organism Choice of oral antifungal
Dermatophyte
  • 1st line: terbinafine
  • 2nd line: itraconazole
Non-dermatophyte (including Candida)
  • 1st line: itraconazole
  • 2nd line: terbinafine

References

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