Scleroderma, also known as systemic sclerosis, is a chronic autoimmune disease characterized by patches of scar-like thick skin.

This rare connective tissue disorder, diagnosed in approximately 1 in 50,000 adults each year in the U.S., is caused by collagen buildup in the area between cells called the stroma.

Scleroderma appears to develop spontaneously, and its underlying causes are still unknown.

How scleroderma develops

Collagen is the most abundant protein in the body, keeping tissues firm and flexible. Specialized cells called fibroblasts produce most of the collagen found in the stroma. Fibroblasts can also recognize and produce chemicals that allow them to communicate with the cells of the immune system.

After an injury, both the immune system and fibroblasts are activated as part of the wound healing process. The immune system protects the injured tissue by keeping viruses and bacteria away, while fibroblasts secrete collagen, creating a scab to rapidly close the wound. Once the danger has passed and damage is repaired, the activating chemical signals are replaced with suppressive ones, stopping the immune reaction and the excessive collagen production by the fibroblasts.

In scleroderma patients, the body keeps producing collagen as if there was a wound that constantly needed to be repaired. Mostly patients’ skin, but other organs as well, can be damaged as a result of collagen accumulating in tissues.

Scleroderma and genetics

Scleroderma does not have a known genetic cause and is not classed as a hereditary disease.  But scleroderma patients often have a family member with another autoimmune disease, like lupus or rheumatoid arthritis, implying that autoimmune diseases may have a heritable element.

More women —about four times as many — are affected by scleroderma than men, and the disease most commonly develops between ages 25 and 55. This distinction in age and gender may indicate an unidentified connection between the disease and a person’s hormonal state.

In the U.S., African-Americans and American Indians are more often affected by scleroderma than Caucasians, suggesting a genetic disposition in these ethnic groups.

Environmental factors

Some evidence points to possible environmental triggers of scleroderma. For example, infections by some bacteria or viruses and long-term exposure to some chemicals, such as pesticides, silica dust, or polyvinyl chloride, are thought to be linked to the disease.

Variations in the type of exposure and disease symptoms, however, work against establishing a cause and consequence relationship between such triggers and scleroderma.


 Scleroderma News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.