An update on the use of hydroxychloroquine in cutaneous lupus erythematosus: A systematic review.

BACKGROUND: Hydroxychloroquine is widely used for the treatment of cutaneous lupus erythematosus (CLE). Although new recommendations exist for hydroxychloroquine dosing, there is still uncertainty about the dosage that will elicit a satisfactory response in CLE while limiting adverse effects, specifically retinopathy. OBJECTIVE: To summarize hydroxychloroquine dosages, outcomes, and adverse effects in the treatment of CLE, focusing on retinopathy. METHODS: A comprehensive literature search from inception to December 2018 was performed in Ovid MEDLINE, Ovid Embase, and The Cochrane Library (Wiley). Studies were screened against predefined inclusion and exclusion criteria. RESULTS: Twelve studies were selected and included 5 retrospective studies, 3 prospective studies, 2 case series, and 2 randomized controlled trials. These studies show that a hydroxychloroquine dosage up to 400 mg/d is effective for most CLE patients (range of effectiveness, 50%-97%), with few adverse effects. One incidence of retinopathy, after a very high cumulative dose, was reported across all 12 studies (852 total patients). LIMITATIONS: Because retinopathy and other serious adverse effects may not appear until much later, many of these studies are limited by short follow-up time. CONCLUSIONS: This evidence suggests that hydroxychloroquine for CLE is effective at 400 mg/d, with an exceedingly low incidence of retinopathy and other adverse effects.