There are many types of psoriatic arthritis that can be classified into one of the following areas:
Asymmetric oligoarthritis. This means that it involves just a few joints and that you can have one hand affected but not another, etc. This is a common form of psoriatic arthritis and sometimes involves deformity of the affected joints. The fingers and toes are usually involved in the beginning and the fingers can look like sausages, a condition called “dactylitis”.
Symmetric Polyarthritis. This involves inflammation of the same joints on either side of the body. Only a few pairs of joints may be involved or many joints can be involved. Common patterns include the hands, wrists or ankles. The tenderness and joint deformity tend to be less than with rheumatoid arthritis.
Distal Interphalangeal Arthropathy. This involves an arthritic experience in the end joints of the fingers and toes. This can occur in regular osteoarthritis as well but, with skin findings, it is usually psoriatic arthritis. Only about 5-10 percent of psoriatic arthritis will have this kind of arthritis. Commonly, the nails are involved with psoriasis as well. You can also get inflammation of the tissue around the nail bed, called a paronychia.
Arthritis mutilans. This is a longstanding form of psoriatic arthritis that involves many joints and that damages the joints so severely that they are deformed. The hands and feet are especially deformed. Up to 16 percent of those with psoriatic arthritis can get this type; bone can soften and dissolve so that the joint may be obliterated. You can get what’s called an “opera glass hand”, in which the joints and fingers themselves become shortened and skin folds appear, covering the fingers and the hand. Men get this more frequently than women do.
Spondylitis. This involves an inflammation of the vertebral joints in the spine. It can also involve a condition known as sacroiliitis, where the sacrum and the pelvis are involved. About five percent of sufferers of psoriatic arthritis get this kind of arthritis and the vast majority are men. It can occur in the presence or absence of other kinds of psoriatic arthritis. The condition doesn’t have to involve the entire spine and can just involve the lower back or the neck.
Juvenile psoriatic arthritis. This is a type of arthritis that affects children around the ages of 9-10 years of age, particularly in girls. It involves 8-20 percent of all arthritis in children. It is usually mild and affects just one or two joints but can last until adulthood. Tendon inflammation is common in this disorder, up to 30 percent of affected kids. Nails are involved in more than 70 percent of cases and problems with bone growth are common and occur in up to half of all affected children. Sacroiliitis can happen in up to 30 percent of children with this disease. The arthritis happens before the skin psoriasis in more than fifty percent of affected children.