What is psoriatic arthritis? Psoriatic arthritis can occur in people who have psoriasis (scaly red and white skin patches). It affects the joints and areas where tissues attach to bone. The joints most often affected are: The outer joints of the fingers or toes. Wrists. Knees. Ankles. Lower back.

What is cicatricial alopecia? Cicatricial alopecia is a group of conditions that destroy hair follicles. Hair follicles are the part of the skin where the hair grows. The follicles are replaced with scar tissue. This means the hair will fall out and not grow back.

What is hidradenitis suppurativa? Hidradenitis suppurativa is a skin disease that causes pimple-like bumps or boils on and under the skin. The disease is chronic (long lasting) and can be painful. HS does not spread from one person to another. HS starts in the hair follicle in the skin and happens where areas of skin may touch or rub together. Poor personal hygiene habits, such as not bathing or shampooing your hair, do not cause HS. In most cases, the cause of the disease is unknown.

What is reactive arthritis? Reactive arthritis is pain or swelling in a joint that is caused by an infection in your body. You may also have red, swollen eyes and a swollen urinary tract. These symptoms may occur alone, together, or not at all. Most people with reactive arthritis recover fully from the first flare of symptoms and can return to regular activities 2 to 6 months later. Some people will have long-term, mild arthritis. A few patients will have long-term, severe arthritis that is difficult to control with treatment and may cause joint damage.

What is scleroderma? Scleroderma is an autoimmune connective tissue and rheumatic disease that causes inflammation in the skin and other areas of the body. This inflammation leads to patches of tight, hard skin. Scleroderma involves many systems in your body. A connective tissue disease is one that affects tissues such as skin, tendons, and cartilage. There are two major types of scleroderma: Localized scleroderma only affects the skin and the structures directly under the skin. Systemic scleroderma, also called systemic sclerosis, affects many systems in the body. This is the more serious type of scleroderma and can damage your blood

What is osteonecrosis? Osteonecrosis is a bone disease. It results from the loss of blood supply to the bone. Without blood, the bone tissue dies. This causes the bone to collapse. It may also cause the joints that surround the bone to collapse. If you have osteonecrosis, you may have pain or be limited in your physical activity. Osteonecrosis can develop in any bone, most often in the: Thigh bone (femur). Upper arm bone (humerus). Knees. Shoulders. Ankles. It is also called: Avascular necrosis. Aseptic necrosis. Ischemic necrosis.

What is acne? Acne is a common skin condition that happens when hair follicles under the skin become clogged. Oil and dead skin cells plug the pores, and outbreaks of lesions (often called pimples or zits) can happen. Most often, the outbreaks occur on the face but can also appear on the back, chest, and shoulders. For most people, acne tends to go away by the time they reach their thirties, but some people in their forties and fifties continue to have this skin problem.

What is alopecia areata? Alopecia areata is a disease that attacks your hair follicles (the part of your skin that makes hair). In most cases, hair falls out in small, round patches about the size of a quarter. This causes only a few bare patches. Some people may lose more hair. In only a few people, the disease causes total loss of hair on the head or loss of all body hair. Your hair may grow back, even if you lose all of it. But it may fall out again. No one can tell you when it might fall out

What is fibromyalgia? Fibromyalgia is a long-lasting or chronic disorder that causes muscle pain and fatigue (feeling tired). If you have fibromyalgia, you have pain and tenderness throughout your body. Sometimes you may have two or more chronic pain conditions at the same time, such as: Chronic fatigue syndrome. Endometriosis. Irritable bowel syndrome. Interstitial cystitis. Temporomandibular joint dysfunction (TMJ). Vulvodynia.