Higher Odds of Adverse Cutaneous Reactions in Patients With Dermatomyositis Treated With Hydroxychloroquine Compared...

Hydroxychloroquine (HCQ) use for the treatment of dermatomyositis (DM) has been associated with adverse cutaneous reactions. We applied a new user, active comparator, retrospective design to assess differences in adverse cutaneous reactions or hospitalizations between HCQ and methotrexate (MTX) use among patients with DM.

We used a national network of data from insurance registries (TriNetX), enrolling patients with two International Classification of Diseases (ICD) codes for DM separated by 6 months or more who had a prescription for either (but not both) HCQ or MTX on or after DM diagnosis. Outcomes were adverse cutaneous reactions (ICD codes) or hospital admission (Current Procedural Terminology (CPT) codes) within 4 months from the prescription dispense date. Logistic regression was used to produce adjusted odds ratios (aORs) and 95% confidence intervals (CIs) comparing outcomes in the HCQ group (n = 1364) and the MTX group (n = 1400), adjusted for age at first DM diagnosis, year of birth, sex, and time from DM diagnosis to first prescription.

Overall, we found no significant difference in odds of hospitalization in those taking HCQ (aOR 1.05; 95% CI: 0.79-1.39) compared with those on MTX. Patients with DM on HCQ had 30% higher odds of adverse cutaneous reaction diagnosis compared with patients on MTX (aOR 1.30; 95% CI: 1.02-1.59). Age at DM diagnosis was an effect modifier of this association, with higher odds of adverse cutaneous reaction among patients taking HCQ who were younger at diagnosis.

Compared with MTX use, HCQ use, especially in younger patients, may result in higher odds of adverse cutaneous reactions.