Effectiveness of chondroitin sulphate in patients with concomitant knee osteoarthritis and psoriasis: a randomized, double-blind, placebo-controlled study.

OBJECTIVE The aim of the trial was to assess the efficacy of chondroitin sulphate (CS) on symptomatic knee osteoarthritis (OA) associated to psoriasis. METHODS In this randomized, double-blind, placebo (PBO)-controlled clinical trial 129 patients with symptomatic knee OA and concomitant psoriasis were randomized into two groups receiving 800 mg daily of CS or PBO for 3 months. The primary efficacy outcome for knee OA was the Huskisson's visual analogue scale (VAS) and for psoriasis was the Psoriasis Area and Severity Index (PASI). Additionally, other secondary efficacy criteria for both conditions were assessed. RESULTS After 3 months of treatment, CS was more effective than PBO, relieving pain VAS (CS -26.9+/-24.8 vs PBO -14.23+/-20.8mm, P<0.01), decreasing the Lequesne index (CS -4.8+/-3.4 vs PBO -3.3+/-3.5, P<0.05) and reducing the number of patients using acetaminophen as rescue medication (CS 43% vs PBO 64%, P<0.05). Regarding PASI, Overall Lesion Severity Scale and Physician's Global Assessment of Change no statistically significant changes were detected in front of PBO. However, CS improved plantar psoriasis compared to PBO (CS 87% vs PBO 27%, P<0.05). Quality of life improved significantly in CS-treated patients according to the Short Form-36 health survey and the Dermatology Life Quality Index (DLQI). CS tolerability was excellent. Adverse events were infrequent and evenly distributed among groups. The incidence of psoriatic flares did not increase after treatments. CONCLUSIONS This study confirms the efficacy and safety of CS as a symptomatic slow-acting drug in patients with knee OA and shows that CS improves plantar psoriasis. The use of CS could represent a special benefit in patients with both pathologies since non-steroidal anti-inflammatory drugs have been reported to induce or exacerbate psoriasis.