Medical Health Encyclopedia

Location of Plaque Psoriasis.

• Patches most often occur on the elbows, knees, and the lower back.
• About half of patients develop psoriasis on the scalp. Many patients have only a few patches in this location. In some cases, however, psoriasis can cover the scalp with thick plaques that may even extend down from the hairline to the forehead. It rarely affects the face in adulthood, however.
• Patches also can appear on the palms and soles, in the genital areas of both men and women, above the pelvic bone, and on the thighs and calves.
• In children, psoriasis is most likely to start in the scalp and spread to other parts of the body; unlike in adults, it also may occur on the face and ears.

Course of Plaque Psoriasis. Plaque psoriasis may persist for long periods. More often it flares up periodically, triggered by certain factors, such as cold weather, infection, or stress.

Psoriatic Arthritis

Description of Psoriatic Arthritis. Psoriatic arthritis (PsA) is an inflammatory condition characterized by stiff, tender, and inflamed joints. About 80% of PsA patients have psoriasis in the nails. Arthritic and skin flare-ups tend to occur at the same time. It is not clear whether psoriatic arthritis is a unique disease or a genuine variation of psoriasis, though evidence suggests they are both caused by the same immune system dysfunction.

Text Continues Below

---

Location of Joint Pain Psoriatic Arthritis. Some experts define five forms of PsA as determined by the location and severity of the joint involvement:

• Symmetric PsA. Symmetric arthritis occurs in the same location on both sides of the body. It usually affects multiple pairs of joints, and, in about half of the cases, the condition will progress. The condition is very similar to but less disabling than rheumatoid arthritis. The psoriasis itself is often severe.
• Asymmetric PsA. Asymmetric PsA involves periodic joint pain and redness, usually only in one to three joints, which can be in the knee, hip, ankle, wrist, or one or more fingers. The pain does not occur in symmetric locations.
• Distal Interphalangeal Predominant (DIP). DIP involves the joints of the fingers and toes closest to the nail and occurs in about 5% of PsA cases.
• PsA in the Spine. Inflammation in the spinal column (spondylitis) is the primary symptom in about 5% of PsA cases. Such patients may experience stiffness and burning sensations in the neck, lower back, sacroiliac, or spinal vertebrae. The spine can be involved in up to three-quarters of all patients with PsA, even though it is not the primary symptom. When it affects the spine, psoriatic arthritis most frequently targets the sacrum (the lowest part of the spine). Movement is difficult.
• Arthritis Mutilans. This is a severe, deforming and progressive arthritis that affects less than 5% of PsA cases. It principally affects the small joints of the hands and feet, but it also frequently affects the neck and lower back. Arthritic and skin flares and remissions tend to coincide.