CASE 6: Nail Psoriasis

By Joe Monroe, PA-C

Focal, painless discoloration of the left thumbnail (A) developed several years earlier in this 46-year-old man. Oral antifungal therapy had no effect on the lesion. Examination reveals yellowish brown spots under the nail. No signs of onychomycosis are seen on other fingers or toes. The presence of plaques with silvery white scale on both elbows corroborates the diagnosis of nail psoriasis. (Case and photographs courtesy of Joe Monroe, PA-C.)Would you prescribe a different antifungal-or consider another approach?
A REVIEW OF THE OPTIONSPsoriasis of the nails may be either an isolated finding or one of several manifestations of the disease. The clinical changes in affected nails include pitting, which occurs most commonly; oil spots; onycholysis; and/or thickened nail plates with subungual hyperkeratosis. Occasionally, very severe disease may cause the nails to crumble (B). Pitting can affect several or all nails; it is characterized by depressions in the nail that are usually smaller than 1 mm in diameter. Oil spots resemble a drop of oil on the surface of the nail plate. Onycholysis presents as a separation of the nail plate from the nail bed. The thickened dystrophic nails with subungual hyperkeratosis that are seen in psoriasis are similar to nails with onychomycosis, a fungal infection. Management of psoriatic nails is extremely difficult and rarely results in complete improvement. Injection of intralesional corticosteroids into the proximal and lateral nail folds is effective; however, this treatment is quite painful and should be considered only for highly motivated patients. Although less effective, a high-potency topical corticosteroid applied to the proximal nail fold may be tried. Psoralen- UV-A (PUVA) therapy or systemic agents, such as methotrexate( or cyclosporine, can be beneficial for psoriatic nails; reserve these modalities for patients with extensive disease that requires more aggressive treatment. (Photograph B courtesy of Drs Sonia Arunabh and K. Rauhila.)CASE 6:
APPROACH AND OUTCOMEReassured and relieved that he did not have a fungal infection, the patient declined treatment.

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