Lesson of the month 2: Fever, arthralgias and hyperkeratotic, scaling and fissuring eruptions of the hands.

A 56-year-old male hairdresser, presented with fever and arthralgias. He had a worsening 'eczematous' palmar rash which had been attributed to irritation from colouring products used in his work. On examination, hyperkeratotic, fissuring eruptions were noted on the palmar side of his fingers and lung auscultation revealed crackles on both lower lobes. Laboratory testing showed elevated muscle enzymes. The clue to the diagnosis in our patient was the presence of hyperkeratotic, fissuring eruptions on the palmar side of his fingers, compatible with 'mechanic's hands'. This is a characteristic semiology reminiscent of hands of manual workers, resembling hand eczema. 'Mechanic's hands', fever, arthralgias, lung findings and elevated serum muscle enzymes raised the possibility of antisynthetase syndrome. Testing for myositis autoantibodies revealed anti-Jo-1 and anti-Ro52 reactivity supporting the diagnosis.Greater awareness of the typical clinical feature of 'mechanic's hands' will allow for earlier diagnosis and appropriate treatment in patients with antisynthetase syndrome. © Royal College of Physicians 2019. All rights reserved.