Introduction
This topic covers systemic connective tissue disease and its common features, and rheumatism (rheumatic fever): its definition, cause, pathogenesis and the diagnosis of the main organ lesions.
Rheumatism in general
- Rheumatism: any disease marked by inflammation and pain to joints, muscles or fibrous tissue. Types include back pain, tendinitis/bursitis, capsulitis, neck pain, osteoarthritis.
- Many are autoimmune, including ankylosing spondylitis, systemic lupus erythematosus and rheumatoid arthritis; gout is crystal-induced, not autoimmune.
- Such autoimmune cases result from T-cell activation and chronic inflammation of the joints and connective tissue, leading to formation of granulation tissue around the tissue (in arthritis, granulation tissue forms around the synovial lining).
Rheumatic fever
Rheumatism is known as rheumatic fever, defined as a Systemic Recurrent Nonsuppurative Allergic inflammatory disease.
- Caused by group A streptococci (GAS), Streptococcus pyogenes.
- A complication of untreated pharyngeal infection; it follows group A streptococcal pharyngitis by about 2-3 weeks.
Mechanism / Pathogenesis
- Immunologically mediated.
- Initiation of type 2 and type 3 hypersensitivity reactions.
- This produces antibodies (Abs) against several streptococcal antigens (Ag).
- The Abs cross-react against cardiac Ags, namely myocardial myosin, sarcolemmal and vascular intimal structures.
- Hereditary factors also play a part.