BH18 A rare case of nail sarcoidosis presenting as an ulcerated nail tumour in a Afro-Caribbean patient

Abstract Sarcoidosis is a multisystem granulomatous disorder that can affect all organs of the body. The disease course can vary from a self-limiting illness to a chronic disease with flares and relapses (Momen SE, Al-Niaimi F. Sarcoid and the nail: review of the literature. Clin Exp Dermatol 2013; 38: 119–24). Nail sarcoidosis is rare and frequently is associated with chronic systemic sarcoidosis (Ward R, Kalus A, Schachtel A. Nail sarcoidosis. JAMA Dermatol 2022; 158: 1202). We report a rare case of nail sarcoidosis in an Afro-Caribbean patient known with a family history of ocular sarcoidosis. A 34-year-old Afro-Caribbean man was referred by rheumatology to dermatology for evaluation of left-thumbnail changes in the setting of known biopsy-proven sarcoidosis involving the skin, scrotum, testis, joints and bones, diagnosed 1 year prior. The patient described a 3-month history of a new, tender, left-thumbnail lesion. At the time of referral to dermatology, his scrotal and skeletal sarcoidosis had not been fully controlled on single-agent methotrexate 20 mg weekly, so adalimumab 40 mg fortnightly had been added with subsequent discontinuation of methotrexate after 2 months of dual therapy. On examination, there was a destructive process affecting the nail plate with an ulcerated nodule present over the lunular area of the nail plate. There was an associated paronychia of the proximal nailfold as well as longitudinal ridging. There was no pigment evident and no abnormalities of the other nails. A full-skin exam was unremarkable. An urgent incisional biopsy of the left nailbed was performed to exclude a subungual melanoma. Histology demonstrated noncaseating granulomatous inflammation consistent with sarcoidosis. Left-hand radiography revealed a lace-like pattern of osteolysis, most notable in the proximal phalanxes of the middle, ring and little fingers and the distal phalanx of the thumb, consistent with skeletal manifestations of sarcoidosis. There was a subsequent flare in the sarcoidal nodules on his proximal upper limbs. Plaquenil 200 mg twice daily was added, with a marked improvement in both his cutaneous and nail sarcoid. We present this interesting case to highlight the awareness of nail sarcoid being a possible cause of a destructive nail process in this population group, with the aim of increasing awareness of nail sarcoidosis and the extent of possible systemic involvement. We highlight the usefulness of nailbed biopsy and X-ray of the hands in this case, in addition to the importance of thorough systemic evaluation and investigations where appropriate in sarcoidosis.