Sarcoid and the nail: review of the literature.

Nail involvement in sarcoidosis is rare, but its presence is often associated with chronic systemic disease. We have reviewed all 33 reported cases of nail involvement with sarcoidosis, including our own case. Nail changes in sarcoidosis, while rare, can include dystrophy (n=10, 30%), onycholysis (n=7, 21%), subungual hyperkeratosis (n=7, 21%), nail hyperkeratosis (n=2, 6%) and longitudinal ridging (n=8, 24%). All reported cases of nail sarcoidosis occurred in the setting of systemic involvement. In almost half of the cases, bony cysts were noted on radiological examination. The presence of nail dystrophy in a patient with sarcoidosis should therefore prompt radiological examination and investigation for systemic involvement.