What Is Scleroderma? 'Full House' Actor Bob Saget Raised Awareness After Sister's Death

U.S. Comedian Bob Saget has died at the age of 65. He was known for playing the character of Danny Tanner in the television series Full House.

Saget was found dead in a hotel room in Florida on January 9, according to police. His cause of death is yet to be determined. Tributes have poured out.

Aside from his comedy career, Saget was known to have been an advocate for people battling with the chronic autoimmune disease scleroderma, which his sister, Gay Saget, had died with in her 40s.

Saget told the National Institutes of Health's MedlinePlus magazine in 2019: "My sister, Gay Saget, was a school teacher near Philadelphia. She was 44 when she was diagnosed with systemic scleroderma.

"She got treatment, but it was just treating her symptoms with drugs like prednisone and cortisone. She had to move to Los Angeles to live with my parents because she needed so much help. She passed away just two years later.

"It is incredibly painful to have a loved one experience a condition like this. It is a very painful disease."

Saget was on the board of directors for the Scleroderma Research Foundation for over a decade and had hosted their events for around 25 years.

Scleroderma is a disease that causes the hardening and tightening of the skin and connective tissue, according to Mayo Clinic. It is generally classed as an autoimmune disease, meaning the body's immune system attacks healthy cells. It is not contagious or cancerous.

Aside from its effect on the skin, scleroderma can also cause inflammation and scarring of many body parts, leading to problems in the lungs, kidneys, heart, intestinal system and more.

Estimates on prevalence vary. The American College of Rheumatology states that around 75,000 to 100,000 people in the U.S. have the disease, mostly women between the ages of 30 and 50. However, the National Scleroderma Foundation states that an estimated 300,000 Americans have the disease.

There are two major forms of Scleroderma: localized scleroderma and systemic scleroderma. In localized scleroderma the changes are usually found in only a few places on the skin and muscles. It can present itself as areas of hardened skin.

Systemic scleroderma may affect the skin as well as internal organs. The tissue of these organs may become hard, causing them to work less efficiently.

It is unclear what causes scleroderma, which results from the overproduction of a key bodily protein called collagen, Mayo Clinic states. Risk factors may include: genetics, environmental triggers (such as viruses), medications or harmful substances, and ongoing immune system problems.

Treatment of scleroderma may involve various different medications to alleviate individual symptoms. Muscle pain may be treated with anti-inflammatory drugs, for instance. However, there is no drug that has been clearly proven to stop or reverse skin hardening, according to the American College of Rheumatology.

Research is ongoing into new treatments.

Information on living with scleroderma can be found on the Scleroderma Research Foundation and National Scleroderma Foundation websites.

Bob Saget
Late U.S. comedian Bob Saget, pictured at an event in Beverly Hills, California, in November, 2021. The comedian had been an activist against the disease scleroderma. Phillip Faraone/Getty