It is an autoimmune disorder caused by formation of auto antibody against group-A β-haemolytic streptococcal protein and protein and reacts against some tissue antigen resulting into inflammatory changes in tissue and characterized by arthritis and carditis etc.
It usually affects children (most common between 5 and 15 years) or young adults.
Pathogenesis of Rh fever: There is a well defined association between group-A β-haemolytic streptococcal pharyngitis and Rheumatic fever. After pharyngeal infection with group-A β-haemolytic streptococci, specific antibody is produced against cell wall constituents (N-acetyl-glycosamine) of the bacteria. Due to similarity of streptococcal antigens with that of cardiac tissue or other connective tissue antigens, a cross reaction takes place between streptococcal antibodies have been identified that cross react with the following four cellular & tissue targets-
- Cardiac myofibre smooth muscle antigen.
- Heart valve fibroblast antigen.
- Heart valve & other connective tissue & cardiac nuclei.
- Neuronal antigen in sub-thalmic & caudate nuclei.
- Exact aetiology is unknown.
- May be due to-
a) Cold weather.
c) Unhygienic condition.
d) Poor socio-economic condition.
e) Upper RTI by streptococcus β-hemolyticus.
- If there is-
a) H/O sore throat 2-3 weeks ago before symptoms appear.
b) Strep β-hemolyticus is isolated from thorat swab.
c) ASO titre high during attack.
Jones criteria for the diagnosis of Rheumatic fever:
- a) Carditis.
- c) Chorea.
- d) Erythma marginatum.
- e) Subcutaneous nodules.
c) Previous rheumatic fever.
d) Raised ESR or CPR.
f) First degree AV block.
Diagnosis: According to jone’s criteria 2 or more major manifestation criteria or 1 major and 2 or more minor manifestation criteria plus evidence of preceding streptococcal infection.
[A] Evidence of a systemic illness (non-specific):
- Raised ESR.
- Raised C-reactive protein.
[B]Evidence of preceding streptococcal infection (specific):
- Throat swab culture: Group-A β-haemolytic streptococci (also from family membrane & contents)
- ASO titres (anti-streptolysin-O antibodies): Rising titres or levels of >200 U (adult), >300U (children)
[C]Evidence of carditis:
- Chest X-ray (P/A view):
- ECG findings:
-First degree or second degree heart block.
-Features of pericarditis.
-T wave inversion.
-Reduciton in QRS voltages.
- No H/O sore thorat.
- Usually after 20 years of age.
- Involves small joints of hands and feet and wasting of muscles above and below the involved joints.
- H/O trauma, joints are not involved.
- X-ray finding-positive.
- No cardiac finding.
[C]Acute Gouty arthritis:
- Sudden involvement of 1st metacarpophalangeal joints.
- Cellulitis of local skin.
- No cardiac sign.
- High serum uric acid.
- Pericarditis & pericardial effusion.
- Heart failure.
- Mitral valvular disease (MS and or MR)
- Aortic valvular disease (AS and or AR)
- Rarely PS or PR and TS or TR.
[A] Symptomatic and supportive treatment:
- Bed rest: until
- The patient is feeling well.
- Symptoms have subsided.
- Pain & fever is absent.
- The patient is gaining wt.
- Sleeping pulse rate is normal.
- Hb% level is improving.
- Leucocytosis & ESR become normal.
- Tab. Aspirin, Tab. Prednisolone.
- Treatment of heart failure, mitral regurgitation or aortic regurgitation (if present).
[B]Anti-streptococcal therapy: Inj. Benzathine penicillin, Pheenoxymethyl penicillin.
[C]Follow up by echo, yearly or 2 yearly for 10 years.
- Davidson’s Principles and Practices of Medicine, 21st edition.