15. Psoriatic arthritis (PsA) is not RA
Psoriatic arthritis is a form of inflammatory arthritis often misdiagnosed as rheumatoid arthritis, but the cause and many treatments are different. “The key distinction is that only patients who have psoriasis develop psoriatic arthritis,” says Dr. Marchetta.
Also, RA symptoms tend to be symmetrical—you have the same joint pain on both sides—while psoriatic arthritis symptoms can be asymmetric. Until 2013, the only medications approved by the FDA to treat psoriatic arthritis were RA drugs.
