Joints, skin both affected by psoriasis
By Graciela Gutierrez
The first symptom of psoriasis is usually an itchy rash, but in some cases, it's more than just the skin that is affected by the disease, say doctors at Baylor College of Medicine.
"Psoriasis is an autoimmune disease," said Sylvia Hsu, M.D., professor of dermatology at BCM. "In about 10 percent of cases the disorder will affect the joints, a condition known as psoriatic arthritis."
Itchy rash first sign
Because an itchy rash, caused by an overproduction of skin cells, is generally the first sign of psoriasis, many people think it is solely a skin disorder. It is usually limited to a few patches of skin but most commonly affects the scalp, elbows and knees. The rash can heal and come back throughout a person's life.
"Joint problems usually don't appear at the same time skin problems do," said Hsu. "Skin issues might appear first, and then years later the joints start to become inflamed, or vise versa."
Joint problems less severe
In most cases the joint problems aren't severe, Hsu said. Many people may find they are stiff in the morning or become achy as the day goes on.
The cause of the disorder isn't fully understood but it is attributed to an abnormality in the immune system involving T cells, which help coordinate immune responses.
"We see a higher level of T cells in psoriasis skin plaques," said Hsu. "We also see elevated levels in the affected joints."
Treatment options
Treatment for the two symptoms can be given separately by a dermatologist or a rheumatologist since the skin and joint problems can appear at different times. A form of treatment known as biologic therapy can be used to treat both. It can be given through injection and works by targeting the specific immune pathways that cause inflammation on the skin and in the joints.
"There is no cure for psoriasis but as doctors begin to better understand the cause of the disorder, therapies are becoming more effective and longer-lasting," said Hsu.
