[Onychomycosis in the elderly]. / Onychomycoses chez les sujets âgés.

BACKGROUND: Onychomycosis is more frequent in the elderly. The aim of this Tunisian study was to determine the prevalence and the epidemiological, clinical and mycological characteristics of onychomycosis in elderly subjects. PATIENTS AND METHODS: This was a prospective study performed over a 7-month period (October 2005 - April 2006). The fingernails and toenails of 290 new consecutive patients aged 65 years and over presenting at general practitioners' clinics were examined by certified dermatologists. Clinical signs of onychomycosis were observed in 120 patients. 137 nail samples and 103 skin scrapings were obtained from these subjects. RESULTS: The study population comprised 51 men and 69 women (sex ratio M/F: 0.74) of mean age 72.33 +/- 6.2 years. Fingernails were involved in 28 cases (20.4%), toenails in 109 cases (79.5%), and both fingernails and toenails in 17 cases (12.4%). On average, patients had 2.7 infected fingernails and 3.9 infected toenails. The big toenail and thumbnail were affected most often respectively on the feet and on the hands. Among the clinical presentations seen, distolateral subungual onychomycosis was the most common clinical presentation, on both the feet and the hands. Mycologically confirmed onychomycosis was detected in 110 of 137 nail samples. The rate of positivity was 80.3%. The prevalence of onychomycosis was confirmed in 34.1% of patients examined (99/290). Dermatophytes were the main agents causing onychomycosis in our population (79%). The most frequently detected fungus was Trichophyton rubrum (72.1%). In toenail infections, dermatophytes were most frequently isolated (97%), while in fingernail infections, yeasts were most often isolated (75%), with Candida albicans being dominant (60%). No moulds were isolated in either the hands or the feet. The same fungus was isolated in both skin scrapings and nail samples from 33 patients. Trichophyton rubrum was detected in 28 cases. CONCLUSION: This study confirms a higher prevalence of onychomycosis in the elderly. It shows dermatophytes, in particular Trichophyton rubrum, to be the most frequently isolated causative agents in onychomycosis in the elderly, followed by yeasts, with no moulds being detected.