Mechanics Hands Synthetase — SCE Rheumatology MCQ

Instant feedback + full explanation. One question, done properly.

EasyMyositisMechanics Hands SynthetaseSCE Rheumatology

A 40-year-old woman with inflammatory myopathy develops rough, hyperkeratotic, fissured skin along the lateral aspects of her fingers, consistent with mechanic's hands. Which autoantibody specificity is most strongly associated with this finding?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: E — Anti-aminoacyl-tRNA synthetase (for example, anti-Jo-1)

Mechanic's hands are strongly associated with anti-aminoacyl-tRNA synthetase antibodies and should suggest antisynthetase syndrome. Anti-Jo-1, directed against histidyl-tRNA synthetase, is the most common specificity; others include anti-PL-7, anti-PL-12, anti-EJ and anti-OJ. Associated manifestations include interstitial lung disease, inflammatory arthritis, myositis, Raynaud phenomenon and fever, although the complete phenotype need not be present simultaneously. Anti-HMGCR and anti-SRP are principally associated with immune-mediated necrotising myopathy rather than mechanic's hands. Anti-TIF1γ is associated with dermatomyositis and an increased malignancy risk in adults, while anti-Mi-2 is associated with a classic dermatomyositis cutaneous phenotype. Neither is the characteristic antibody association of mechanic's hands.

Reference: Gusdorf L et al. Mechanics hands in patients with antisynthetase syndrome: 25 cases. Ann Dermatol Venereol. 2019;146(1):19-25. https://pubmed.ncbi.nlm.nih.gov/30595338/