The epidemiology of onychomycosis: possible role of smoking and peripheral arterial disease

ABSTRACT Background Onychomycosis is a relatively common condition the aetiology of which appears to be multifactorial, with both genetic and acquired factors being responsible. In our clinical practice we have observed that smokers and individuals with peripheral arterial disease may have an increased prevalence of onychomycosis compared to normal individuals. Patients and methods Patients attending a vascular clinic in a hospital were asked about a history of smoking and peripheral arterial disease. The lower extremity was assessed for peripheral arterial disease. Material was obtained from toenails for mycological evaluation. Results Two hundred and fifty‐four patients (male 146, female 108; age, mean ± standard error, 66.6 ± 0.8 years) were enrolled. Abnormal‐appearing nails and onychomycosis were present in 49.2% and 22.4% of patients, respectively. Factors associated with onychomycosis included, increasing age (risk odds ratio [ROR] 1.05, P = 0.002), male gender (ROR 1.7, P = 0.09), smoking (packs per day) (ROR 1.9, P = 0.02) and peripheral arterial disease (ROR 4.8, P = 0.02). Conclusions The factors predisposing to the development of onychomycosis are multifactorial. Both smoking (number of packs of cigarettes consumed per day) and peripheral arterial disease are independent predictors of onychomycosis. Awareness of these factors may help in the prevention of onychomycosis and the optimal management of this disease.