Mixed connective tissue disease features signs and symptoms of a combination of disorders — primarily of 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 may swell up like sausages, and the fingertips might turn white and become numb. In later stages, some organs — such as the lungs, heart and kidneys — may be affected.
Mixed connective tissue disease occurs most commonly in young women. Treatment often includes drugs such as prednisone.
Early indications of mixed connective tissue disease may include:
- General feeling of being unwell. This malaise may be accompanied by increased fatigue and a mild fever.
- Cold and numb fingers. One of the most common early indicators is known as Raynaud's phenomenon — in which your fingers feel cold and numb, often in response to cold or stress. Fingers may turn white and then purplish blue when the blood vessels constrict. After warming, the blood vessels relax, blood flow resumes and the fingers turn red. Toes also can be affected.
- Swollen fingers. Many people who have mixed connective tissue disease experience swelling in their hands and fingers, sometimes to the point where the fingers resemble sausages.
- Muscle and joint pain. Mixed connective tissue disease also can result in muscle aches and joint swelling and pain. In some cases, the joints may become deformed, similar to what is seen in rheumatoid arthritis.
When to see a doctor
Make an appointment with your doctor if you have signs and symptoms that are bothersome or interfere with your daily routine — particularly if you've already been diagnosed with lupus or another connective tissue disease.
Doctors don't know what causes mixed connective tissue disease. The disease is part of a larger group of diseases known as autoimmune disorders.
When you have an autoimmune disorder, your immune system — responsible for fighting off disease — mistakes normal, healthy cells for intruders. In connective tissue diseases, your immune system mistakenly attacks the fibers that provide the framework and support for your body.
While mixed connective tissue disease can happen to anyone, including children, it appears to be most common in women under the age of 30.
Mixed connective tissue disease can lead to serious complications, including:
- Lung problems. High blood pressure affecting the arteries in your lungs (pulmonary hypertension) is the most common cause of death in people with mixed connective tissue disease.
- Heart disease. Mixed connective tissue disease sometimes results in the enlargement of parts of the heart and inflammation around the heart.
- Kidney failure. The kidney damage caused by mixed connective tissue disease can progress for years without producing any signs or symptoms, but it can eventually result in kidney failure.
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. If you take corticosteroids, your doctor will likely monitor you for adverse effects, such as osteoporosis, muscle weakness and infection.
Preparing for your appointment
You're likely to first bring your concerns to your family doctor. He or she may refer you to a rheumatologist, a doctor who specializes in joint diseases.
What you can do
Before your appointment, you may want to write a list of answers to the following questions:
- Has anyone in your immediate family had similar problems?
- Have you been diagnosed with any other medical problems?
- What medications and supplements do you take regularly?
What to expect from your doctor
Your doctor is likely to ask you a number of questions, including:
- When did you begin experiencing symptoms?
- Have your symptoms been continuous or occasional?
- How severe are your symptoms?
- What, if anything, seems to improve your symptoms?
- What, if anything, appears to worsen your symptoms?
Tests and diagnosis
Your doctor may suspect mixed connective tissue disease based on your signs and symptoms. A physical exam may reveal signs such as swollen hands and painful, swollen joints. A blood test can determine whether you have a certain antibody in your blood that indicates mixed connective tissue disease.
Treatments and drugs
There's no cure for mixed connective tissue disease, but medication can help manage the signs and symptoms of the disease. Mild forms of mixed connective tissue disease may not require treatment. You may require treatment only during flares or, if you have a more serious form of the disease, you may require continuous medication.
The type of medication prescribed depends on the severity of your disease and the symptoms you have. Medications may include:
- Corticosteroids. Drugs such as prednisone help control your immune function, keeping it from attacking healthy cells, and suppress inflammation. Side effects can include mood swings, weight gain, high blood sugar, increased blood pressure, weakened bones and cataracts.
- Other immunosuppressants. Other treatments may be based on your signs and symptoms. For instance, if the symptoms you're experiencing are similar to those of lupus, your doctor may suggest trying medications typically prescribed for people with lupus.
Lifestyle and home remedies
Other methods to control symptoms of mixed connective tissue disease include:
- Protect hands from cold. Raynaud's phenomenon, which causes cold and numb fingers, is a common symptom of mixed connective tissue disease. Wearing gloves and taking other measures to keep your hands warm can help.
- Stop smoking. Smoking causes blood vessels to constrict, which can worsen the effect of Raynaud's phenomenon.
- Reduce 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.