Mechanic's hands: a characteristic cutaneous sign of antisynthetase syndrome

"Mechanic's hands" are a characteristic cutaneous sign of idiopathic inflammatory myositis. We describe the case of a 61-year-old male patient who was diagnosed with idiopathic polymyositis and non-specific interstitial lung disease in 1999, and three years later developed scaly, fissured hyperkeratotic lesions on the lateral and palmar surfaces of the first three fingers of both hands, with little pruritus. The presence of the anti-Jo-1 antisynthetase antibody in the patient's serum, the finding of skin lesions characteristic of "mechanic's hands" and the patient's other systemic clinical manifestations made it possible to establish the diagnosis of "antisynthetase syndrome."