BACKGROUND: The involvement of Candida in the pathogenesis of chronic paronychia (CP) has never been proven, even though this condition is commonly considered a type of Candida onychomycosis. OBJECTIVE: The purpose of this study was to compare the efficacy of systemic antifungals (itraconazole or terbinafine) with a topical corticosteroid (methylprednisolone aceponate) in the treatment of patients with CP. METHODS: The study involved 45 adult patients with CP. Medication was given in a randomized, double-blind and double dummy manner over 3 weeks. Patients were then followed for 6 weeks. Clinical and mycologic evaluations were performed at baseline, and at weeks 3 and 9. The efficacy measures included clinical and photographic evaluation. RESULTS: Of 48 nails treated with methylprednisolone aceponate, 41 were improved or cured at the end of the follow-up period. The statistical analysis showed a significant difference between the number of nails improved or cured by methylprednisolone aceponate and that of nails improved or cured with terbinafine (30 out of 57) or itraconazole (29 out of 64). Presence of Candida was not strictly linked to disease activity, and Candida eradication was associated with clinical cure in only 2 of the 18 patients who carried Candida at the beginning of the study. CONCLUSION: This study shows that topical steroids are more effective than systemic antifungals in the treatment of CP, and supports the view that CP is not a type of onychomycosis but a variety of hand dermatitis caused by environmental exposure.