CASE 6: Nail Psoriasis

Focal, painless discoloration of theleft thumbnail (A) developed severalyears earlier in this 46-year-old man.Oral antifungal therapy had no effecton the lesion.Examination reveals yellowishbrown spots under the nail. No signsof onychomycosis are seen on otherfingers or toes. The presence ofplaques with silvery white scale onboth elbows corroborates the diagnosisof nail psoriasis.(Case and photographs courtesy of Joe Monroe, PA-C.)Would you prescribe a differentantifungal-or consider anotherapproach?A REVIEW OF THE OPTIONSPsoriasis of the nails may be eitheran isolated finding or one of severalmanifestations of the disease.The clinical changes in affected nailsinclude pitting, which occurs mostcommonly; oil spots; onycholysis; and/or thickened nail plates with subungualhyperkeratosis. Occasionally,very severe disease may cause thenails to crumble (B).Pitting can affect several or allnails; it is characterized by depressionsin the nail that are usuallysmaller than 1 mm in diameter. Oilspots resemble a drop of oil on thesurface of the nail plate. Onycholysispresents as a separation of the nailplate from the nail bed. The thickeneddystrophic nails with subungual hyperkeratosis that are seen in psoriasisare similar to nails with onychomycosis,a fungal infection.Management of psoriatic nails isextremely difficult and rarely resultsin complete improvement. Injectionof intralesional corticosteroids into theproximal and lateral nail folds is effective;however, this treatment is quitepainful and should be consideredonly for highly motivated patients. Althoughless effective, a high-potencytopical corticosteroid applied to theproximal nail fold may be tried. Psoralen-UV-A (PUVA) therapy or systemicagents, such as methotrexate orcyclosporine, can be beneficial for psoriaticnails; reserve these modalitiesfor patients with extensive disease thatrequires more aggressive treatment.(Photograph B courtesy of Drs Sonia Arunabh andK. Rauhila.)CASE 6:APPROACH AND OUTCOMEReassured and relieved that hedid not have a fungal infection, the patientdeclined treatment.