Unfortunately, many people with psoriatic arthritis do not know they have it. A survey conducted by the National Psoriasis Foundation found that up to one-third of people with psoriasis said they had suffered from persistent joint stiffness for at least 3 months, but had yet to be diagnosed with psoriatic arthritis.
Psoriatic arthritis may go undiagnosed because it can be hard to identify. The disease varies widely in its initial symptoms and its differing degrees of severity. The symptoms of psoriatic arthritis may develop slowly or appear quickly and relentlessly.
In up to 20 percent of cases, the signs and symptoms of psoriatic arthritis present before the skin lesions common in psoriasis. Other times, the psoriatic arthritis symptoms and psoriasis symptoms arrive simultaneously. In the majority of cases, however, psoriatic arthritis appears after psoriasis has begun to flare. Sometimes patients do not experience the symptoms of psoriatic arthritis until 10 years after the first symptoms of psoriasis.
Symptoms of Psoriatic Arthritis
The joints most often affected by psoriatic arthritis are those of the knee, ankle and feet. Usually, only a few joints are swollen at a time. Like the symptoms of psoriasis, the symptoms of psoriatic arthritis can flare and then subside. Sometimes the same joints are inflamed on both sides of the body; sometimes only one side of the body is affected. In either case, the affected joints become painful, swollen and warm. These symptoms are also typical of rheumatoid arthritis and provide another explanation of how psoriatic arthritis can be misdiagnosed or undiagnosed.