Overlap syndromes are autoimmune conditions that are characterized by overlapping clinical features of two or more connective tissue diseases (CTDs). These syndromes are difficult to diagnose and treat because of their complex nature. While some overlap syndromes are well-known, there are other overlap syndromes that are less common but equally important to understand.
MCTD is an overlap syndrome that combines features of systemic lupus erythematosus, scleroderma, and polymyositis. It is characterized by the presence of high levels of antibodies against ribonucleoproteins (RNP). MCTD is primarily seen in women, and symptoms include Raynaud's phenomenon, arthritis, muscle weakness, and skin changes.
SS is an overlap syndrome that combines features of rheumatoid arthritis and systemic lupus erythematosus. It is characterized by the destruction of the glands that produce tears and saliva. SS primarily affects women, and symptoms include dry eyes, dry mouth, joint pain, and fatigue.
UCTD is an overlap syndrome that includes features of several CTDs but does not meet the diagnostic criteria for any specific disease. It is characterized by the presence of autoantibodies and symptoms such as joint pain, muscle weakness, and Raynaud's phenomenon. UCTD can progress to a specific CTD or remain undifferentiated.
OSM is an overlap syndrome that combines features of systemic lupus erythematosus and myositis. It is characterized by muscle weakness, skin rashes, and joint pain. OSM is rare, and its cause is not known. Treatment involves the use of immunosuppressive drugs and steroids.
Overlap syndromes are challenging to diagnose and treat because of their complexity. However, early diagnosis and treatment are crucial for preventing complications and improving quality of life. If you experience symptoms of an overlap syndrome, talk to your doctor about getting a proper diagnosis and treatment plan.