[Onychomycosis frequency in psoriatic patients in a tertiary care hospital].

BACKGROUND The changes in psoriatic nails can closely resemble an onychomycosis. Therefore, the fungal infection may be underdiagnosed. It was investigated the frequency of mycosis in fingernails and toenails in 150 patients with psoriasis in a dermatology department. METHODS The clinical data suggestive of onychomycosis were investigated. Nail scales were obtained and cultured on Sabouraud dextrose agar with and without antibiotic. A direct examination with KOH was also performed. RESULTS Out of 150 patients, 67 (45 %) had healthy nails; 42 (28 %) presented onychomycosis and 41 (27 %) showed nail changes without infection. Fingernail changes were more associated with psoriatic onychopathy (82.5 %), unlike toenail changes that were more frequently caused by fungal infection (26.4 % vs. 9.45 % in psoriasis). Out of 20 positive cultures, 22 fungi were isolated, of which 11 belonged to Candida spp. (50 %). As risk factor to develope an onychomycosis, only the psoriasis evolution time showed a significant difference (p = 0.033). CONCLUSIONS In patients with psoriasis, fingernail disorders are mainly due to the own disease, while toenail disorders changes can be associated with onychomycosis. The main etiological agents were yeasts from the genus Candida. The only factor associated with a higher incidence of onychomycosis in these patients was a long lasting psoriasis.