Mixed connective tissue disease (MCTD) has signs and symptoms of a combination of disorders — primarily lupus, scleroderma, and polymyositis. Many people with this uncommon disease also have Sjogren's syndrome. For this reason, mixed connective tissue disease (MCTD) is sometimes called an overlap disease.
In mixed connective tissue disease, the symptoms of the separate diseases usually don't appear all at once. Instead, they tend to occur over a number of years, which can complicate diagnosis.
Early signs and symptoms often involve the hands. Fingers might get puffy, and the fingertips become white and numb, often in response to cold exposure. In later stages, some organs — such as the lungs, heart and kidneys — can be affected.
There's no cure for mixed connective tissue disease. Treatment depends on how severe the disease is and the organs involved.
Early indications of mixed connective tissue disease can include:
- General feeling of being unwell. This can include increased fatigue and a mild fever.
- Cold and numb fingers or toes (Raynaud's phenomenon). In response to cold or stress, your fingers or toes might turn white and then purplish blue. After warming, the fingers or toes turn red.
- Swollen fingers or hands. Some people have swelling of the fingers.
- Muscle and joint pain. Joints can become inflamed, swollen and deformed, similar to what occurs with rheumatoid arthritis.
- Rash. Red or reddish brown patches can appear over the knuckles.
When to see a doctor
See your doctor if you have signs and symptoms that interfere with your daily routine — particularly if you've been diagnosed with lupus or another connective tissue disease.
Mixed connective tissue disease is an autoimmune disorder, although the cause isn't known. In autoimmune disorders, your immune system — responsible for fighting off disease — mistakenly attacks healthy cells.
In connective tissue diseases, your immune system attacks the fibers that provide the framework and support for your body. Some people with mixed connective tissue disease have a family history of the condition. But the role of genetics in the disease remains unclear.
Mixed connective tissue disease can occur in people of any age. However, it appears to be most common in women under the age of 50.
Mixed connective tissue disease can lead to serious complications, some of which can be fatal. Complications include:
- High blood pressure in the lungs (pulmonary hypertension). This condition is a major cause of death in people with mixed connective tissue disease.
- Interstitial lung disease. This large group of disorders can cause scarring in your lungs, which affects your ability to breathe.
- Heart disease. Parts of the heart can enlarge, or inflammation can occur around the heart. Heart failure can occur.
- Kidney damage. About one-fourth of people with mixed connective tissue disease develop kidney problems, Kidney involvement is usually mild, but can lead to kidney failure.
- Digestive tract damage. Commonly, mixed connective tissue disease affects the digestive tract. You might have abdominal pain and problems with swallowing and digesting food.
- Anemia. About 75% of people with mixed connective tissue disease have iron deficiency anemia.
- Tissue death. People with severe Raynaud's disease can develop gangrene in the fingers.
- Hearing loss. In one small study, hearing loss was reported in almost half the patients with mixed connective tissue disease. More research is needed to understand this association.
- Nerve damage. Sjogren syndrome can affect the nerve that carries feeling from your face to your brain (trigeminal nerve). If you have trigeminal neuralgia, even mild stimulation of your face — such as from brushing your teeth or putting on makeup — can trigger a jolt of severe pain.