Nail psoriasis - a treatment challenge.

Nail involvement in psoriasis is common and mostly occurs with other lesions but can also occur alone. Besides psychosocial and aesthetic impairments, patients often complain about functional impairment. Nail psoriasis is a predictor for more severe psoriasis, decreased quality of life, and a higher risk for the development of psoriatic arthritis. Onychomycosis and other differential diagnoses should be excluded prior to treatment. This article presents an overview of different clinical appearances of nail psoriasis, the essential diagnostic assessment before treatment, important differential diagnoses, and published data on treatment options for nail psoriasis.