In a class of diseases known as autoimmune disorders, the body's immune system attacks its own tissues. Some of these diseases are similar to each other. They may involve arthritis and inflammation of arteries in the tissues. People who developed these disorders were previously said to have "connective tissue" or "collagen vascular" disease. We now have names for many specific conditions such as:
- Ankylosing spondylitis
- Polyarteritis nodosa
- Psoriatic arthritis
- Rheumatoid arthritis
- Systemic lupus erythematosus
When a specific disease cannot be diagnosed, more general terms may be used. These are called undifferentiated systemic rheumatic (connective tissue) diseases or overlap syndromes.
Bennett RM. Overlap syndromes. In: Firestein GS, Budd RC, Gabriel SE, McInnes IB, O'Dell JR, eds. Kelley and Firestein's Textbook of Rheumatology. 10th ed. Philadelphia, PA: Elsevier; 2017:chap 86.