Prevalence of tinea pedis in psoriasis, compared to atopic dermatitis and normal controls--a prospective study.

There are discrepancies in the literature regarding the prevalence of tinea pedis in psoriasis. The aim of this investigation was to conduct a cross-sectional study of the prevalence of tinea pedis in psoriasis compared to atopic dermatitis patients and normal controls. We enrolled 232 psoriatic patients, 190 atopic dermatitis patients and 202 normal controls, between the years 2010 and 2013. The prevalence of tinea pedis was 13.8% in psoriasis patients, not significantly different from that in atopic dermatitis patients 8.4% (P = 0.092)), but significantly higher than in normal controls 7.4% (P = 0.043). Both gender and age affected the prevalence of tinea pedis in psoriasis and normal controls, while only age affected the prevalence of tinea pedis in atopic dermatitis. Regarding gender, there was higher prevalence of tinea pedis in men: 19.1% (P = 0.019) in psoriasis and 12.1% (P = 0.013) in normal controls. Age affected the prevalence of tinea pedis in normal controls (P < 0.001), psoriasis patients (P = 0.001) and atopic dermatitis patients (P = 0.001), with higher prevalence with increasing age. Trichophyton rubrum was the most common species in psoriasis (71.9%), atopic dermatitis (75.0%) and normal controls (73.3%). Our study found a relatively high prevalence of tinea pedis among psoriasis patients.