By:Dawit Ayele

Definition  Rheumatic fever is an inflammatory disease that occurs as a delayed, non-suppurative sequela of upper respiratory infection with group A streptococci.

Etiology  Antecedent infection with specific microorganism- Gp A streptococci  At specific site- upper respiratory tract-nowhere else  Heavily encapsulated, as evidenced by their growth as mucoid colonies on blood agar plates.  Predominant strains 3, 5, 18, 24, and others

Epidemiology  3% of individuals with untreated gp A streptococci will develop RF.  Most often occurs in children; the peak age- related incidence is b/n 5 and 15 years.  Risk factors for outbreak: -lower standards of living esp.crowding, -the organism itself -the degree of host/herd immunity to the prevalent M-types in an affected community

Pathogenesis  Study Hypothesis of ‘antigenic mimicry’: 1)Similarity between the group-specific CHO of the gp A streptococcus & the glycoprotein of heart valves, -2)the molecular similarity among the streptococcal cell membrane, strept M ptn sarcolemma,& other moieties of human myocardial cell.  Possiblity of predisposing genetic influence  differences in immune response to strept

Clinical feature -- most notably affect the heart, joints, skin, subcutaneous tissue, and central nervous system. POSSIBLE FEATURES  High fever, prostration, crippling polyarthritis  Lassitude, tachycardia, new cardiac murmurs  Acute pericarditis  Fulminant heart failure  Sydenham's chorea without fever or toxicity  Acute abdominal pain mimicking appendicitis  Varying combinations of the above

Diagnosis  No specific test to establish Dx  *Clinical+supportive evidence from microbiology & clinical immunology lab  1944 Jones proposed standard criteria  1992 updated Jones published by AHA  To fullfill the dx requires either 2 major or 1 major & 2 minor + evidence of antecedent streptococcal infection

The Jones Criteria Major  Carditis  Migratory polyarthritis  Sydenham’s chorea  Subcutaneous nodules  Erythema marginatum + Supporting evidence of a recent gp A strept infection(throat culture or rapid antigen /ab test ASO-80%+) Minor  Clinical-fever -arthralgia  Lab- ↑ acute phase reactants- ( ↑ ESR) -prolonged PR

Carditis  40-60% of RF cases have evidence of carditis  Pancarditis involve- pericardium, myocardium& endocardium  Cx-sinus tachycardia, -murmur of MR -S3 gallop -pericardial friction rub -cardiomegaly 20%-subtle mitral valve abnormality w/o audible murmur(echo dx)

Carditis…  Commonly affected valves: -Mitral(pure ms or ms/mr) -Aortic-isolated is rare-mitral valve is almost always simultaneously affected -tricuspid & pulmonic –not commonly affected

Migratory Polyarthritis  In as many as 75% of cases  Extremely painful joint pain & swelling  Most often affects-ankles, wrists,knees& elbows  Not usually affected-small joints of hands or feet;seldom involves hip joints

Sydenham’s chorea  CNS d/o  <10% of patients  It may happen in as long as several months from initial strept infection

Subcutaneous nodules & erythema marginatum  Uncommon manifestations  Nodules found over extensor surface of joints  Are seen most often in patients with long standing Rheumatic heart dis.  EM usually concentrated on the trunk as evanescent macular eruption with rounded borders

Treatment Two necessary therapeutic approach to ARF pts 1)Anti –Strept antibiotic treatment:for all patients with ARF whether culture is +/- Conventional-10 days course of oral penicillin v 5oo mg po bid or erythromycin for penicillin allergy Choise of many-Benz. Penicillin G 1.2 mill IU 2)Treatment for clinical manifestation of the disease-arthritis-ASA upto 2 gm qid -CHF –conventional medical measures -Chorea-reassurance for most-resolves in 6wks to 6 mths

2 o prophylaxis  AHA recommendations- Benzanthine penicillin 1.2 million IU IM Q 4 weeks or for oral penicillin V(250mg 2x/day)or oral sulfadiazine 1 gm daily.  For those with higher risk Benz. Penicillin q 3 wks is more effective in decreasing risk of recurrence.  Risk of recurrence is highest during the 1 st 5 yrs after attack—2ry prophylaxis is always given for at least these period.  Continued rx for high risk exposure gp- students,teachers,medical& military personnel.  Many believe  documented recurrences &/or documented RVD should receive 2 0 px for life!!

THANK YOU