In osteoarthritis (OA), the common NSAID treatment can aggravate psoriasis in those who have it. In one study, 129 people with knee OA and accompanying psoriasis took 800 mg of chondroitin sulfate per day or a placebo. After three months, OA pain in the chondroitin group had decreased 1.5 to 2 times the rate for the placebo group. Psoriasis of the soles of the feet (plantar) decreased 27 percent for the placebo group and 87 percent for the chondroitin group.
Doctors said these findings confirm chondroitin is safe and could have special benefit for those with both OA and psoriasis because NSAIDs can aggravate psoriasis and trigger flare-ups.