Sarcoidosis presenting as nail dystrophy

A 45-year-old woman was referred to the dermatology clinic for assessment of "refractory onychogryphosis." She had a 3-year history of lesions involving distal phalanges of the first and third of her left foot. Initially she described periungual erythema and swelling. Three weeks later she noted a whitish growth and thickening of her third toenail. X-ray films of the digit were reported as normal. Several months later the same changes occurred in her great toe. These lesions were asymptomatic. There was no history of trauma. Numerous fungal cultures were negative. No light microscopic examinations were undertaken. She had a trial of both topical and systemic terbinafine of 3-months duration with no clinical improvement. Several clinical opinions were obtained from two dermatologists, a surgeon, and a chiropodist. Past medical history of note was significant for tubal ligation, cervical cancer, and chronic sinusitis. The latter condition in retrospect was thought to be secondary to sarcoidosis. Physical examination revealed periungual violaceous discolouration of the first and third toes of the left foot. There was evidence of significant nail changes including dystrophy, onycholysis, and hyperkeratosis (Fig. 1). The fingernails were normal. There were no other skin abnormalities. A punch biopsy of the tip of the third toe showed granulomatous inflammation. There was evidence of hyperkeratosis, exocytosis, and a dense infiltrate composed of collections of histiocytes and a few giant cells forming granulomas (Fig. 2). Repeat x-ray films of the foot showed soft tissue swelling of the first and third digits. There was bony resorption in the distal phalanges with a lacey trabecular pattern compatible with sarcoidosis (Fig. 3). Chest x-ray films revealed marked hilar adenopathy. The patient was sent to a respirologist who concurred with the diagnosis of sarcoidosis. Further investigations included a low serum calcium of 2.07 mmol/L, serum ACE of 70 U/L (upper limit of normal is 75), Wintrobe erythrocyte sedimentation rate (ESR) of 10 mm per hour, thyroid stimulating hormone concentration of 0.65 mU/L, and a urinary calcium excretion rate that was elevated at 7.3 mmol/day. Pulmonary function tests were unremarkable. The patient was initially treated with clobetasol under occlusion and intralesional triamcinolone with minimal improvement. She was subsequently started on prednisone, 15 mg per os daily because of the lung and bone involvement with significant improvement noted in the toe lesions with diminution of both the swelling and violaceous discolouration.