A total of 87 papers were included (518 patients). Overall the quality of the studies was low (mostly grade B and C).
Biologics: Total of 44% showed a significant response to adalimumab, 35% had a moderate response and 21% did not respond to adalimumab (15 papers, 68 patients). Thirty-nine percent of patients taking etanercept showed a significant response to treatment, 17% had a moderate improvement and 44% did not respond (nine papers, 54 patients). Fifty percent of patients had a significant response with infliximab, 39% showed a moderate response and 11% showed no response (42 papers, 147 patients). Two patients showed a significant response to ustekinumab, one patient had a moderate response and one did not respond to treatment (two papers, four patients).
Retinoids: Eighteen percent of the patients had a significant improvement with isotretinoin , 17% had a moderate improvement and 64% had no response with the treatment (seven papers, 174 patients). Seventy-three percent of patients treated with acitretin and etretinate had a significant improvement, 23% had a moderate response and 5% did not respond to therapy (six papers, 22 patients).
Other treatments: Thirty-five percent of patients treated with dapsone had a significant improvement, 21% had a moderate improvement and 44% did not respond to therapy (three papers, 34 patients). Twenty-five percent of patients treated with colchicine had a moderate response and 75% did not respond to treatment (one paper, eight patients). Fifty percent had a significant response with ciclosporin treatment and another 50% had a moderate response (three papers, four patients). None of the patients responded to treatment with methotrexate (one paper, three patients).
Further data on relapse rates and adverse events were reported in the review. The highest number of withdrawals due to adverse events occurred with infliximab and isotretinoin.