Wolstencroft PW, et al. - In this retrospective cohort study, researchers identified disease features that increase the risk of hydroxychloroquine-associated skin eruption in adults with dermatomyositis. In a US cohort of patients with dermatomyositis, adverse skin reactions to hydroxychloroquine were relatively common. The findings from the present study suggested that pathophysiologic differences exist between autoantibody subsets in dermatomyositis.

Methods

• This investigation was performed in the outpatient dermatology clinic at a tertiary academic referral center.
• Eligibility criteria included all adults with dermatomyositis (age >18 years) who started receiving hydroxychloroquine between July 1, 1990, and September 13, 2016.
• Participants in the study were considered to have a hydroxychloroquine-associated skin eruption if a skin eruption had developed within their first 4 weeks of treatment and resolved with discontinuation of hydroxychloroquine therapy.
• One or more doses of hydroxychloroquine was the main exposure analyzed in this research.
• Main outcomes and measures were the correlations between autoantibodies (against transcription intermediary factor 1γ [TIF-1γ], nucleosome-remodeling deacetylase complex [Mi-2], nuclear matrix protein [NXP-2], small ubiquitinlike modifier 1 activating enzyme [SAE-1/2], melanoma differentiation-associated gene 5 [MDA-5], histidyl–transfer RNA synthetase [Jo-1], Ku, and signal recognition particles) and cutaneous adverse reactions to hydroxychloroquine in patients with dermatomyositis.

Results

• Inclusion criteria were met by 111 subjects, and 23 (20.7%) developed a hydroxychloroquine-associated skin eruption (20 [87.0%] were women with a mean [SD] age of 49 [14] years at diagnosis).
• Compared with patients without the autoantibody (16 of 97 [16.5%]), skin eruptions were approximately 3 times more common in patients with anti–SAE-1/2 autoantibodies (7 of 14 [50.0%]).
• It was observed that none of 15 subjects with anti–MDA-5 autoantibodies had a skin eruption vs 23 of 96 (24.0%) of those without the autoantibody.
• In exact logistic regressions adjusted for age, race/ethnicity, sex, amyopathic status, anti–Ro52 status, and dermatomyositis-associated cancer, the presence of anti–SAE-1/2 autoantibodies was significantly related to a hydroxychloroquine-associated skin eruption (odds ratio [OR], 8.43; 95% CI, 1.98-49.19; P=.003).
• It was noted that the presence of anti–MDA-5 autoantibodies was significantly negatively associated with a hydroxychloroquine-associated skin eruption (OR, 0.06; 95% CI, 0.0004-0.52; P=.006).
• Findings revealed that no other autoantibodies were significantly positively or negatively related to a hydroxychloroquine-associated skin eruption.