Nail psoriasis: clinical presentation and best practice recommendations.

Nail involvement in psoriasis is common and can have a significant impact on quality of life. Manifestations of nail dystrophy in psoriasis include pitting, onycholysis, subungual hyperkeratosis and splinter haemorrhages. Clear evidence regarding the range of treatment options for nail psoriasis is lacking. Topical therapies, including corticosteroids and vitamin D(3) analogues, are simple to administer and readily available, but are not effective in treating all types of psoriatic nail dystrophy. Other topical agents have been tried, but may be less readily available. Intralesional corticosteroid injections can be helpful, but may be painful and time consuming. Psoralen plus ultraviolet A treatment has been shown to improve subungual hyperkeratosis, onycholysis, discolouration and nail crumbling, but not pitting. The possibility of future harm with other types of radiation treatment, including superficial radiotherapy and Grenz rays, limits their use. The use of systemic therapies, including the recent introduction of biological agents, is largely restricted to those with concomitant widespread cutaneous or joint involvement because of cost implications and potential toxicity. Further studies regarding the treatment of nail psoriasis are required in order to ascertain the best regimen of therapy for each patient.