Connective Tissue Diseases

What is connective tissue disease?

“Connective tissue disease” is an umbrella term for a wide range of diseases that can affect your connective tissues. These are the tissues that connect and support your organs and body structure. They hold your muscle fibers together and cover and protect your nerves. They also include your:

• Body fat
• Bones
• Cartilage
• Fascia
• Ligaments
• Skin
• Tendons

As these tissues are in almost every part of your body, connective tissue diseases can also affect you all over. They might affect one or two types of tissues throughout your body or many. They can also affect many organs. Different types of connective tissue disease have different symptoms.

What are the different types of connective tissue disease?

There are over 200 known connective tissue disorders. They fall into three main categories:

• Autoimmune diseases
• Genetic disorders
• Cancers (sarcomas)

Autoimmune connective tissue diseases

Autoimmune diseases are what many people think of when they think of connective tissue disease. In these conditions, your immune system generates chronic inflammation in some parts of your body. Chronic inflammation causes pain, swelling and, eventually, permanent damage to your tissues.

Some examples of autoimmune connective tissue disorders include:

• Rheumatoid arthritis: This causes joint inflammation, sometimes leading to joint destruction and deformity. In some cases, the inflammation may spread to your blood vessels or other organs.
• Relapsing polychondritis: This causes inflammation and degeneration of the cartilage in your ears, nose and throat, which can affect your hearing and breathing. Sometimes, it affects your eyes.
• Myositis: This causes inflammation and degeneration of your muscles, making them feel weak. There are different types of myositis that can affect both the muscles and/or skin, causing rashes.
• Sjögren’s syndrome: This inflames and damages your moisture-producing glands, causing dryness throughout your body, including your eyes, mouth, digestive system and respiratory system.
• Lupus: This condition can cause inflammation in any of your connective tissues, and sometimes all of them. Systemic lupus may affect your skin, joints and vital organs, like your heart, lungs and kidneys.
• Scleroderma: This condition causes your body to overproduce collagen, which can cause thickening and hardening of your skin and organs, including your digestive system, kidneys, heart and lungs.

If you have overlapping features of several autoimmune connective tissue disorders, it’s called mixed connective tissue disease. If you have some symptoms of some autoimmune diseases, but they don’t meet the criteria for any specific disorder, it’s called undifferentiated connective tissue disease.

Genetic connective tissue disorders

Genetic disorders of the connective tissue result from a gene mutation that you inherit at birth. The mutation affects how your connective tissues develop. It usually affects one of the two primary building blocks in all connective tissues: collagen or elastin. This causes various defects in your tissues.

Examples of hereditary connective tissue diseases include:

• Marfan syndrome: This syndrome affects the elastin fibers that give your tissues elasticity, making your tissues too loose. It causes elongated limbs and can also cause issues in your cardiovascular system.
• Ehlers-Danlos syndrome: This condition weakens the collagen throughout your body, making your skin and joints hyperextendable, fragile and unstable. It can also affect your cardiovascular system.
• Osteogenesis imperfecta: This causes a lack of type 1 collagen, which is prominent in your ligaments, bones and teeth. It also makes your joints loose and your bones and teeth brittle and weak.
• Stickler syndrome: This syndrome affects the collagen in your cartilage and in the gel-like substance that lubricates your eye (vitreous humor). It can also cause hearing and vision issues, as well as arthritis.
• Epidermolysis bullosa: This affects the collagen in your skin, making it fragile and causing chronic blistering. It can also affect the mucous membranes that line your mouth, throat and airway.
• Loeys-Dietz syndrome: This condition affects the signals that tell your connective tissues how to develop. It can also lead to a variety of musculoskeletal abnormalities, as well as an enlarged aorta in your heart.

People born with these conditions can have a wide variety of symptoms and complications, ranging from mild to severe. As healthcare providers can’t treat the genetic defect, they treat the symptoms and complications individually as much as they can. They’ll monitor your condition throughout your life.

Cancers of the connective tissues

The type of cancer that can start in your connective tissues is called sarcoma. Sarcomas can start in your bones, cartilage, fat, muscles, ligaments, tendons or the deep layers of your skin. They can also start in other “soft tissues” that aren’t technically connective tissues, like epithelium and endothelium.

Examples of connective tissue sarcomas include:

• Osteosarcoma: The most common type of primary bone cancer
• Chondrosarcoma: Bone cancer that starts from cartilage
• Ewing sarcoma: A tumor that can start in your cartilage or bone
• Fibrosarcoma: Starts in fibrous tissues, like ligaments and tendons
• Clear cell sarcoma: Starts in the muscles, tendons or fascia of your legs
• Liposarcoma: A tumor that starts in your body fat
• Dermafibrosarcoma: Starts in the middle layer (dermis) of your skin
• Myxofibrosarcoma: Starts as a lump under your skin, usually in an arm or leg

What are symptoms of connective tissue disease?

Different connective tissue diseases can cause a wide variety of different symptoms. But there are some common themes. For example, most connective tissue diseases can cause symptoms all over your body. Musculoskeletal pain, weakness and/or stiffness are common, as are systemic symptoms, like fatigue.

Many connective tissue disorders can affect your lungs and cardiovascular system. Your lungs have a lot of connective tissues and rely heavily on them. Blood vessels run through most of your connective tissues, and because they're made of similar stuff, inflammation spreads easily between them.

As a result, many connective tissue diseases can cause musculoskeletal symptoms together with cardiopulmonary symptoms, like shortness of breath and changes to your blood pressure or heartbeat. If your blood vessels become inflamed, they can swell and break, causing unexplained bleeding.

Sarcomas often won’t cause symptoms until they grow large enough to compress an organ or vessel. But some can cause bone pain or joint pain where they start. Others may appear as a lump under your skin that may or may not be tender. Most sarcomas can spread, causing more widespread symptoms.

What causes connective tissue disease?

Connective tissue disease happens when something in your body malfunctions. In autoimmune disease, your immune system launches an attack against your own body. In genetic diseases, a mutated gene causes your tissues to develop wrong. Cancer happens when cells continue to divide uncontrollably.

For the most part, scientists don’t know the underlying reasons why these malfunctions occur. But certain risk factors might play a part in making you more vulnerable to these diseases. Severe infections that overstress your immune system and exposure to certain toxic chemicals are possible risk factors.

How are connective tissue diseases diagnosed?

Your doctor may order various tests depending on what type of connective tissue disorder is suspected. They’ll first ask for your medical history and a family history, and will do a physical examination. Further tests may include:

• Imaging tests, such as X-rays and magnetic resonance imaging (MRI) scans.
• Tests for markers of inflammation, such as C-reactive protein and Erythrocyte sedimentation rate (ESR).
• Tests for antibodies, especially for autoimmune conditions.
• Tests for dry eyes or dry mouth.
• Blood and urine tests.
• A tissue biopsy.

How do you treat connective tissue disease?

Most connective tissue disorders are lifelong conditions. Healthcare providers do what they can to reduce their severity and treat the symptoms and complications individually. Autoimmune diseases and sarcomas can go into remission — periods without any signs or symptoms. But they can also recur (return).

Healthcare providers treat autoimmune diseases with a combination of anti-inflammatory drugs (corticosteroids) and immune system-repressing drugs (immunosuppressants) to stop the automatic inflammation. Treatments for sarcomas include surgery, chemotherapy and radiation therapy.

Scientists are researching genetic therapies that may one day be able to reduce the effects of genetic connective tissue disorders. For now, providers can only treat the symptoms. In addition to medications, they recommend regular low-stress exercise or physical therapy to help manage musculoskeletal pain.

How do I take care of myself while living with connective tissue disease?

The wide range of connective tissue disorders have very different outlooks and possible complications. Your healthcare provider is the best person to tell you what signs and symptoms to look out for and when to seek treatment. They may also recommend lifestyle changes to help optimize your overall health.