Nail Involvement in Psoriatic Patients and Association with Onychomycosis: Results from a Cross-Sectional Study Performed in a Military Hospital in Tunisia.

Nail psoriasis has variable prevalence and heterogeneous aspects. Many of them could mimic onychomycosis (OM). It has been suggested that patients with nail psoriasis are at high risk of OM. The aim of our study was to determine the epidemiological and clinical characteristics of nail psoriasis and to estimate the frequency and the factors associated with OM in psoriatic patients. The studied group included 163 patients with psoriasis aged 18 years or older. Epidemiological and clinical data, as well as the severity of skin and nails disease by evaluating the Psoriasis Area Severity Index (PASI) and Nail Area Psoriasis Severity Index (NAPSI) scores were specified. Mycological testing was performed for patients with nail alterations. Nail involvement was found in 71.2% of patients. The most common nail alterations were subungual hyperkeratosis and onycholysis. The mean NAPSI score was 11.6. Mycological testing was performed in 104 patients with onychodystrophy. OM was diagnosed in 53% of the cases. Dermatophytes were the most isolated pathogens. OM was associated with male gender, but not with age, NAPSI, or PASI score. Psoriasis is one of the dermatoses that most commonly affect the nail. Available data about the association between nail psoriasis and OM are controversial. However, mycological testing should be routinely performed on psoriatic nails.