Background While evidence suggests that hydroxychloroquine (HCQ) may decrease the viral load in patients with a COVID-19 infection, a number of case reports indicate adverse dermatologic effects of this potential treatment. Objective To conduct a systematic review of previously reported cases of psoriasis onset, exacerbation, or relapse after HCQ treatment. Methods A comprehensive EMBASE and MEDLINE search of original studies examining adverse effects of HCQ treatment related to psoriasis was conducted. Participant demographics, and details of HCQ administration and psoriasis diagnosis were extracted from 15 articles representing 18 patients. Results Females accounted for a significantly larger number of psoriatic cases compared to males and unreported sex (n=14, 77.8% vs. n=2, 11.1% vs n=2, 11.1% respectively). Additionally, 50% (n=9) of the cases did not have a history of psoriasis prior to taking HCQ. Of the 18 patients, 50.0% (n=9) experienced de novo psoriasis, 27.8% (n=5) experienced exacerbation of psoriatic symptoms and 22.2% (n=4) had a relapse of psoriasis after HCQ administration. Conclusions HCQ treatment may result in induction, exacerbation, or relapse of psoriasis. Monitoring for adverse effects of HCQ treatment is necessary, and clinical trials are essential in characterizing the safety profile of HCQ use in patients with a COVID-19 infection. Capsule Summary
