Management of onychomycosis and awareness of guidelines among dermatologists

Conflicts of interest: none declared. Sir, Onychomycosis is increasing in incidence, may lead to significant morbidity and requires lengthy treatment. Evidence‐based management guidelines on onychomycosis have recently been published by the British Association of Dermatologists (BAD).1 The key recommendations are that mycological confirmation of infection should be obtained before commencing treatment, topical treatments are most suitable for superficial white onychomycosis or very early distal and lateral subungual onychomycosis (DLSO), terbinafine is the systemic antifungal agent of choice in adults with dermatophyte onychomycosis, and an alternative drug with or without nail avulsion should be considered for treatment failures. We undertook an internet‐based survey of clinical practice of 85 BAD member dermatologists (51 consultants and 34 nonconsultants) in connection with these key recommendations. When faced with a case of suspected onychomycosis, all respondents except for one sampled the nail for mycological investigation. Clippings and scrapings (subungual or surface) were the most frequent type of sample obtained (57%), followed by clippings alone (35%) and scrapings alone (7%). In DLSO, the highest yield of dermatophytes is in the most proximally accessible subungual debris,1 which can be easily obtained with a 1‐mm curette. Sampling subungual curettings in addition to nail clippings increases the sensitivity of detecting pathogenic fungi with microscopy by 17% and with culture by 38% compared with obtaining nail clippings alone.2 Microscopy during clinic was performed by only 7%, which may be a reflection of time pressures, inadequate access to equipment and lack of experience. While the rate of sampling was high, 13% treated onychomycosis without evidence of mycological infection. As up to 50% of dystrophic nails do not have onychomycosis,3 it is important to confirm mycological infection before embarking on treatment, to avoid prolonged therapy of uninfected nails as this is costly, unnecessarily exposes patients to the risk of side‐effects, and complicates distinguishing true treatment failures from misdiagnosis.