collagen vascular disease, any of a group of acquired disorders that have in common diffuse immunological and inflammatory changes in small blood vessels and connective tissue. Common features include arthritis, skin lesions, iritis and episcleritis, pericarditis, pleuritis, subcutaneous nodules, myocarditis, vasculitis, and nephritis. Also often associated are Coombs’ test–positive hemolytic anemia, thrombocytopenia, leukopenia, B and T cell abnormalities, antinuclear antibodies, cryoglobulins, rheumatoid factors, false-positive serological test results for syphilis, alterations in serum complement, and immunological abnormalities. The diseases usually included in this category are mixed connective tissue disease, necrotizing vasculitis, and other vasculopathies; polymyositis; relapsing polychondritis; rheumatic fever; rheumatoid arthritis; scleroderma; and systemic lupus erythematosus. The cause of most of these diseases is unknown. Hereditary factors and deficiencies, autoimmunity, environmental antigens, infections, allergies, and antigen-antibody complexes in various combinations are probably involved. Also called connective tissue disease.
