Wolstencroft PW, et al. - In adults with dermatomyositis, researchers assessed disease characteristics that increase the risk of hydroxychloroquine-associated skin eruption via a retrospective cohort study in the outpatient dermatology clinic at a tertiary academic referral center. In a US cohort of patients with dermatomyositis, adverse skin reactions to hydroxychloroquine were relatively common. In dermatomyositis, there are pathophysiologic differences between autoantibody subsets.

Methods

• Eligibility criteria included all adults with dermatomyositis aged >18 years who began receiving hydroxychloroquine between July 1, 1990 and September 13, 2016.
• If a skin eruption developed within the first 4 weeks of treatment and resolved with discontinuation of hydroxychloroquine therapy, patients were deemed to have a hydroxychloroquine-associated skin eruption.
• Associations 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 were the main outcomes analyzed.

Results

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