Treatment of common nail disorders.

Treatment of nail diseases is not always easy; topical treatment is often ineffective because the nail plate is not penetrated by topical drugs, and the nail matrix is located under the proximal nail fold. The most frequent nail disorders are nail psoriasis and onychomycosis. In these cases, systemic treatment is often necessary to cure the nail changes. Systemic treatment with steroids is mandatory for patients with nail lichen planus because the disease may cause definitive destruction of the nail matrix. Environmental nail abnormalities are frequent and include nail brittleness, onycholysis, and chronic paronychia. Preventive measures should always be associated with treatment in these cases.