IL17A and tinea unguium: Table 4 shows that the prevalence of onychomycosis was highest in the methotrexate group (68% in methotrexate treatment, 40% in topical treatment, and 28% in biologic treatment). However, the number of patients with diabetes and wet-work exposure was higher in the methotrexate group than in the other two groups. The risk of Candida colonization of the nail did not increase significantly in the biologic treatment group even though the main biologics used were interleukin-17 inhibitors.