Understanding the five types of psoriatic arthritis can help you identify the first signs and symptoms, which can then lead to a proper diagnosis and treatment from your doctor.
Psoriatic arthritis is a chronic inflammatory disorder that is most commonly associated with the skin condition, psoriasis; however, it is possible to have psoriatic arthritis without psoriasis. Depending on the type of joint affected, it can be categorized into five main types. While you may initially have one type, it can progress to become another.
Understanding the five types of psoriatic arthritis can help you identify the first signs and symptoms, which can then lead to a proper diagnosis from your doctor.
Asymmetric psoriatic arthritis (asymmetric oligoarthritis)
This type of psoriatic arthritis typically affects less than five small or large joints in the body; however, it will affect different joints on both sides (asymmetric arthritis). For example, if your right knee joint is affected, then your left knee joint would not be affected. Asymmetric arthritis can involve any joint in the body. The symptom severity may range from mild to severe. Around 35 percent of patients with psoriatic arthritis fall under this category.
Symmetric psoriatic arthritis (or symmetric polyarthritis)
In symmetric psoriatic arthritis, five or more joints on both sides of your body are typically affected. This means if your right knee joint is affected, then your left knee joint will also be affected. The same goes for other joints in your body as well. Nearly half of patients with psoriatic arthritis have this type, making it the most common form of the condition.
Because rheumatoid arthritis is also symmetric, recognizing symmetric polyarthritis may be initially challenging. However, the symptoms of this type of psoriatic arthritis are milder with less joint deformity than rheumatoid arthritis, and the rheumatoid factor tests negative as well.
Distal arthritis (or distal interphalangeal arthropathy)
This type of psoriatic arthritis impacts the distal interphalangeal joints, which are the end joints of the fingers and toes. Apart from pain, swelling, and redness over these joints, your nails may also show some changes, such as discolored spots, pitting, or separating from the nail bed.
This type is found in about 5 to 10 percent of people affected with psoriatic arthritis. In addition, affected people often have other types of psoriatic arthritis as well.
Spondylitis (or spondyloarthritis)
With psoriatic spondylitis, there is pain and stiffness in the neck, lower back, and sacroiliac joints (the joints connecting the pelvis and lower spine). In the absence of treatment, the vertebrae in the spine can fuse and cause the back to become permanently stiff. You may also develop other types of psoriatic arthritis.
This type makes for about 5 percent of all cases of psoriatic arthritis.
Arthritis mutilans
Though rare, this is the most severe type of psoriatic arthritis that affects less than 5 percent of all patients. This condition can deform and destroy multiple joints in the fingers, hands, wrists, and feet. Because of bone loss, your fingers look like the opening of opera glasses (“opera-glass hand”) or like a telescope (“telescoping finger”).
In arthritis mutilans, you may also have other symptoms, including:
- Stretched, shiny, and wrinkled skin on the fingers
- Stiffness and immobility of the joint (due to fusion of bones)
- The joints and bone tissues in the hands and feet wear down