Chloroquine therapy in psoriatic arthritis.

Our aim was to examine the efficacy of chloroquine in psoriatic arthritis (PsA) and to assess whether chloroquine therapy exacerbated psoriasis. Thirty-two patients had been given chloroquine therapy while attending the University of Toronto Psoriatic Arthritis Clinic. Twenty-four patients continued therapy for at least 6 months, and 18, or 75%, demonstrated > 30% reduction in the actively inflamed joint count. Moreover, there was a significant decrease in the number of actively inflamed joints. A control group, consisting of 24 patients taking no remittive agents, seen during the same period of time, was identified. Only 14, or 58%, of these patients had a > 30% reduction in inflamed joint count over a 6-month period. This pattern was not significantly different (p = 0.19) from the chloroquine treated group. Of the 32 patients who had been given chloroquine, a total of 6 had an exacerbation of psoriasis, only 1 discontinued therapy. There was no case of exfoliative dermatitis. Six of the 24 control patients had an exacerbation of psoriasis. Our experience suggests that chloroquine may be an effective treatment in PsA, and that it does not exacerbate psoriasis. A prospective, randomized, double blind, controlled trial of antimalarial therapy in PsA is warranted.