Mixed connective tissue disease has signs and symptoms of a combination of disorders — primarily lupus, scleroderma and polymyositis. For this reason, mixed connective tissue disease is sometimes referred to as 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 in sequence over a number of years, which can make diagnosis more complicated.
Early signs and symptoms often involve the hands. Fingers might swell like sausages, and the fingertips become white and numb. In later stages, some organs — such as the lungs, heart and kidneys — may be affected.
There's no cure for mixed connective tissue disease. The signs and symptoms are usually treated with certain medications, such as prednisone.
Early indications of mixed connective tissue disease can include:
- General feeling of being unwell. This malaise may be accompanied by 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 experience swelling to the point where the fingers resemble sausages.
- Muscle and joint pain. Joints may become deformed, similar to what occurs with rheumatoid arthritis.
- Rash. Red or reddish brown patches may 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 already been diagnosed with lupus or another connective tissue disease.
The precise cause of mixed connective tissue disease isn't known.
Mixed connective tissue disease is an autoimmune disorder. 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. Researchers are working to identify proteins produced by the immune system that might cause mixed connective tissue disease.
Some people with mixed connective tissue disease have a family history of the condition. But the role of genetics in causing 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 30.
Mixed connective tissue disease can lead to serious complications, including:
- High blood pressure in the lungs (pulmonary hypertension). This condition is the main 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 may become enlarged, or inflammation may occur around the heart. Heart disease is the cause of death in about 20 percent of people with mixed connective tissue disease.
- Kidney damage. About one-fourth of people with mixed connective tissue disease develop kidney problems. Sometimes, that damage can lead to kidney failure.
- Digestive tract damage. You may develop abdominal pain and problems with digesting food.
- Anemia. About 75 percent of people with mixed connective tissue disease have iron deficiency anemia.
- Tissue death (necrosis). People with severe Raynaud's phenomenon can develop gangrene in the fingers.
- Hearing loss. Often unrecognized, hearing loss may occur in as many as half the people with mixed connective tissue disease.
Treatment side effects
Corticosteroids are commonly used to manage the signs and symptoms of mixed connective tissue disease. These medications are effective, but they carry risks.
Your doctor will likely monitor you for adverse effects, such as osteoporosis, muscle weakness and infection. You may need to take calcium and vitamin D supplements to help ease these adverse effects.
You may be referred to a doctor who specializes in joint diseases (rheumatologist).
What you can do
- Write down your symptoms, including any that may seem unrelated to the reason why you scheduled the appointment.
- Write down your key medical information, including other conditions.
- Write down key personal information, including any major changes or stressors in your life.
- Make a list of all your medications, vitamins or supplements.
- Find out if anyone in your family has had similar problems.
- Ask a relative or friend to accompany you, to help you remember what the doctor says.
- Write down questions to ask your doctor.
Questions to ask your doctor
- What's the most likely cause of my symptoms?
- What kinds of tests do I need?
- What treatments are available?
- I have other health conditions. How can I best manage them together?
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask other questions.
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may make time to go over points you want to discuss in-depth. You may be asked:
- When did you begin experiencing symptoms?
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- What, if anything, seems to improve or worsen your symptoms?
Your doctor is likely do these tests:
- Physical exam to check for swollen hands and painful, swollen joints
- Blood test, which can determine whether you have a certain antibody in your blood that is associated with mixed connective tissue disease
There's no cure for mixed connective tissue disease. But medication can help manage the signs and symptoms.
You might need treatment only during flare-ups. If you have a more serious form of the disease, you might need continuous medication.
The type of medication prescribed depends on the severity of your disease and your symptoms. Medications can include:
- Corticosteroids. Drugs, such as prednisone, can help prevent your immune system from attacking healthy cells and suppressing inflammation. Side effects can include mood swings, weight gain, high blood sugar, increased blood pressure, weakened bones and cataracts.
- Antimalarial drugs. Hydroxychloroquine (Plaquenil) can treat mild mixed connective tissue disease and might prevent flare-ups.
- Calcium channel blockers. Medications, such as nifedipine (Procardia) and amlodipine (Norvasc), help relax the muscles in the walls of your blood vessels and may be used to treat Raynaud's phenomenon.
- Other immunosuppressants. Your doctor might prescribe other medications based on your specific signs and symptoms. For example, if they're similar to those of lupus, your doctor might recommend medications typically prescribed for people with lupus.
- Pulmonary hypertension medications. Bosentan (Tracleer) or sildenafil (Revatio, Viagra) may be prescribed.
Your doctor is likely to monitor you closely for signs of pulmonary hypertension.
Other ways to control symptoms of mixed connective tissue disease include:
- Nonsteroidal anti-inflammatory drugs. Medications, such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve, others), may help relieve the pain and inflammation if your condition is mild.
- Protecting hands from cold. Wearing gloves and taking other measures to keep your hands warm can help prevent Raynaud's phenomenon.
- Smoking cessation. Smoking causes blood vessels to narrow, which can worsen the effects of Raynaud's phenomenon.
- Reducing stress. Raynaud's phenomenon is often triggered by stress. Relaxation techniques — such as slowing and focusing on your breathing — can help reduce your stress levels.