Up to 30% of patients with cutaneous lupus erythematosus (CLE) fail to respond to hydroxychloroquine (HCQ).

We sought to evaluate the efficacy of increased daily doses of HCQ on cutaneous response in refractory CLE.

We conducted an open-label prospective study between 2010 and 2014. Patients with CLE and HCQ blood level less than or equal to 750 ng/mL were included. The daily dose of HCQ was increased to reach blood concentrations greater than 750 ng/mL. The primary end point was the number of responders defined by an improvement of CLE Disease Area and Severity Index score (4 points or 20% decrease) in patients with HCQ blood concentration greater than 750 ng/mL.

We included 34 patients (26 women; median age 45 [range 28-72] years). Two nonadherent patients were excluded. The median CLE Disease Area and Severity Index score before treatment was significantly improved after treatment (8 [range 2-30] vs 1.5 [range 0-30]), P < .001). The primary response criterion was reached in 26 (81%) of the 32 patients analyzed. A decrease in HCQ doses without further CLE flare (median follow-up 15.8 [range 3.06-77.4] months) was achieved in 15 of the 26 responders.

The main limitations of the study are its open-label design and the limited number of patients included.

Increasing HCQ doses to reach blood concentrations greater than 750 ng/mL should be considered before addition of other treatments in refractory CLE.