Overview of Scleroderma
Scleroderma is an autoimmune disease that causes inflammation and fibrosis (thickening) in the skin and other areas of the body. When an immune response tricks tissues into thinking they are injured, it causes inflammation, and the body makes too much collagen, leading to scleroderma. Too much collagen in your skin and other tissues causes areas of tight, hard skin. Scleroderma may involve many systems in your body.
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 vessels and internal organs, such as the heart, lungs, and kidneys. This subset is also divided into two additional categories called "limited" and "diffuse" which represents how much skin involvement there is in the body.
There is no cure for scleroderma. The goal of treatment is to relieve symptoms and stop the progression of the disease. Early diagnosis and ongoing monitoring are important.
What happens in scleroderma?
The cause of scleroderma is unknown. However, researchers think that the immune system overreacts and causes inflammation and injury to the cells that line blood vessels. This triggers connective tissue cells, especially a cell type called fibroblasts, to make too much collagen and other proteins. The fibroblasts live longer than normal, causing a buildup of collagen in the skin and other organs, leading to some of the signs and symptoms of scleroderma. There can also be injuries to blood vessels.
Who Gets Scleroderma?
Anyone can get scleroderma; however, some groups have a higher risk of developing the disease. The following factors may affect your risk.
- Sex. Scleroderma is more common in women than in men.
- Age. The disease usually appears between the ages of 30 and 50 and is more common in adults than children.
- Race. Scleroderma can affect people of all races and ethnic groups, but the disease can affect African Americans more severely. For example:
- The disease is more common in African Americans than European Americans.
- African Americans with scleroderma develop the disease earlier when compared with other groups.
- African Americans are more likely to have more skin involvement and lung disease when compared with other groups.
Types of Scleroderma
- Localized scleroderma affects the skin and underlying tissues. Localized scleroderma occurs more commonly in children but can also appear in adults. It generally appears in one or both of these patterns:
- Morphea, or patches of scleroderma that may be a half-inch or larger in diameter.
- Linear scleroderma, when the scleroderma thickening occurs in a line. This usually extends down an arm or leg, but sometimes runs down the forehead and face.
- Systemic scleroderma, sometimes called systemic sclerosis, affects your skin, tissues, blood vessels, and major organs. Doctors usually divide systemic scleroderma into two types based on the degree of skin involvement:
- Limited cutaneous scleroderma, which comes on gradually and affects the skin on your fingers, hands, face, lower arms, and legs below the knees.
- Diffuse cutaneous scleroderma, which comes on more rapidly and starts as being limited to the fingers and toes, but then extends beyond the elbows and knees to the upper arms, trunk, or thighs. This type usually has more internal organ damage.
Symptoms of Scleroderma
The symptoms of scleroderma vary from person to person depending on the type of scleroderma you have.
Localized scleroderma typically causes patches of thick, hard skin in one of two patterns.
- Morphea causes patches of skin to thicken into firm, oval-shaped areas. These areas may have a yellow, waxy appearance surrounded by a reddish or bruise-like edge. The patches may stay in one area or spread to other areas of skin. The disease usually becomes inactive after over time, but you may still have darkened patches of skin. Some people also develop fatigue (feeling tired).
- Linear scleroderma causes lines of thickened or different colored skin to run down your arm, leg, and, rarely, on the forehead.
Systemic scleroderma, also known as systemic sclerosis, may come on quickly or gradually and may also cause problems with your internal organs in addition to the skin. Many people with this type of scleroderma have fatigue.
- Limited cutaneous scleroderma comes on gradually and usually affects skin on your fingers, hands, face, lower arms, and legs below the knees. It often causes problems with your blood vessels and esophagus. The limited form has less frequent major internal organ involvement, such as kidney disease or progressive lung disease, but it is generally milder than in the diffuse form.
- Diffuse cutaneous scleroderma comes on suddenly, usually with skin thickening on your fingers or toes. The skin thickening then spreads to the rest of your body above the elbows and/or knees. This type can damage your internal organs, such as:
- Anywhere along your digestive system.
- Your lungs.
- Your kidneys.
- Your heart.
Causes of Scleroderma
Researchers do not know the exact cause of scleroderma, but they suspect that several factors may contribute to the disease:
- Genetic makeup. Genes can increase the chance for certain people to develop scleroderma and play a role determining the type of scleroderma they have. You cannot inherit the disease, and it is not passed from parent to child like some genetic diseases. However, first-degree relatives of people with scleroderma are at higher risk of developing scleroderma than the general population.
- Environment. Researchers suspect that exposure to some environmental factors, such as some chemicals, may trigger scleroderma.
- Immune system changes. Abnormal immune or inflammatory activity in your body triggers cell changes that cause the production of too much collagen. In some cases, an immune reaction to developing cacner cells may trigger scleroderma.
- Hormones. Women develop most types of scleroderma more often than men. Researchers suspect that hormonal or immunological differences between women and men might play a part in the disease.