Mixed Connective Tissue Disease
Expert diagnosis and personalized treatment at Arthritis Care of Los Angeles.
What is Mixed Connective Tissue Disease?
Mixed connective tissue disease (MCTD) is a rare autoimmune disorder characterized by overlapping features of lupus, scleroderma, and polymyositis. Patients with MCTD may experience symptoms common to these conditions, including joint pain and swelling, muscle weakness, skin changes, and Raynaud's phenomenon (fingers turning white or blue in response to cold or stress). A hallmark of MCTD is the presence of high levels of a specific antibody called anti-U1 ribonucleoprotein (anti-U1 RNP). MCTD can be challenging to diagnose because its symptoms often evolve over time. Some patients initially present with features of one connective tissue disease and develop additional symptoms months or years later. The severity of the condition varies widely — some patients have mild disease that responds well to treatment, while others develop more serious complications involving the lungs, kidneys, or heart. Dr. Forouzesh at Arthritis Care of Los Angeles provides expert evaluation and long-term management of MCTD at both our Culver City and Encino locations. With careful monitoring and individualized treatment, Dr. Forouzesh helps patients manage their symptoms and prevent disease progression.
Common Symptoms
- Raynaud's phenomenon — fingers and toes turning white or blue with cold exposure
- Swollen, puffy fingers (sometimes called 'sausage fingers')
- Joint pain and swelling, often resembling rheumatoid arthritis
- Muscle weakness, particularly in the shoulders and hips
- Fatigue and general malaise
- Skin rashes or tightening of the skin on the hands and face
- Difficulty swallowing due to esophageal dysfunction
- Shortness of breath (may indicate pulmonary involvement)
Experiencing these symptoms? Get expert care today.
How is Mixed Connective Tissue Disease Diagnosed?
Diagnosing MCTD requires recognizing the overlap of symptoms from multiple connective tissue diseases and confirming the presence of the anti-U1 RNP antibody. Dr. Forouzesh performs a comprehensive evaluation including a detailed physical examination and thorough review of symptoms. Blood tests check for anti-U1 RNP antibodies (which are present in high titers in MCTD), antinuclear antibodies (ANA), inflammatory markers, muscle enzymes, and organ function. Pulmonary function tests and echocardiography may be ordered to assess for lung and heart involvement. Because MCTD can evolve over time, ongoing monitoring is essential to detect new symptoms and adjust the diagnosis and treatment plan accordingly.
Treatment Options
Nonsteroidal Anti-Inflammatory Drugs (NSAIDs)
Used to manage mild joint pain and inflammation. NSAIDs may be sufficient for patients with predominantly musculoskeletal symptoms.
Corticosteroids
Prednisone may be prescribed for moderate to severe symptoms, including active joint inflammation, muscle weakness, or organ involvement.
Immunosuppressive Medications
Methotrexate, azathioprine, or mycophenolate may be used to control disease activity and reduce the need for long-term corticosteroids.
Calcium Channel Blockers
Medications like nifedipine help manage Raynaud's phenomenon by relaxing blood vessel walls and improving circulation to the fingers and toes.
Pulmonary Hypertension Management
If pulmonary hypertension develops, targeted therapies such as endothelin receptor antagonists or phosphodiesterase inhibitors may be necessary.
Key Statistics
2-10
Per 100,000 people affected
Source: National Organization for Rare Disorders
80%
Of patients with MCTD are women
Source: American College of Rheumatology
15-25
Most common age of diagnosis (years)
Source: NIH Genetic and Rare Diseases Information Center
Frequently Asked Questions
Ready to Get Expert Care?
Schedule your appointment with Dr. Solomon Forouzesh, MD, FACP, FACR — a board-certified rheumatologist with 50++ years of expertise in arthritis and autoimmune diseases.