Acute rheumatic fever

Inflammatory disease following group A β-hemolytic streptococcal infection, due to cross-reactivity of

antigens

Epidemiology Onset- ~2-3 weeks after streptococcal

infection Rate of development after untreated

infection- ~3% Recurrence with a subsequent

untreated infection- 5-50%, more in patients with RHD

Common in children- age 5-15, only 20% first attacks in adults

Pathogenesis Possible autoimmune disease Follows pharyngitis due to encapsulated GABH

streptococci A complex interplay of genetically determined host

susceptibility, pathogenic GABH streptococcal infection, in a susceptible environment

Best defined virulence factor- M protein Present on surface of bacteria Promotes bacterial adherence & resist phagocytosis Shares homology with cardiac myosin, tropomyosin, keratin,

laminin Types 1,3,5,6,14,18,19,24 associated with ARF Other- T cell activation by streptococcal superantigens,

leading to granuloma formation

Pathology Myocardial Aschoff body- a submiliary

granuloma, later forms scar Endocardial verrucous valvulitis, heals

with fibrous thickening & adhesions, causing stenosis or regurgitation

Serofibrinous pericarditis Joint- exudative arthritis Subcutaneous nodules- granuloma

Modified Jones’ criteria Used for diagnosis 2 major or 1 major+2 minor or

2 minor (in patient with RHD), with evidence of streptococcal infection

Evidence of s’coccal infection within last 45 days-

Elevated/rising ASO/anti-DNase B titres Positive throat culture Rapid Ag test for GABH s’cocci Recent scarlet fever

Jones’ criteria Major Migratory polyarthritis,

involves large joints Carditis- pancarditis Subcutaneous nodules-

painless, extensor Erythema marginatum-

over trunk/arms Sydenham’s chorea

Minor Fever Arthralgia Raised ESR/CRP ECG- heart-block-

prolonged PR interval

Previous e/o rheumatic fever

Acute carditis New murmur or change in pre-existing murmur Apical pansystolic murmur- MR ± Carey Coomb murmur-apical

MDM Basal early diastolic murmur- AR Tachycardia Soft heart sounds New onset CHF- gallop rhythm- S3 Pericardial rub or effusion Cardiomegaly Within 6 months of acute streptococcal infection

Course

90% attacks subside within 12 weeks

<5% persist >6 months

Recurrence

With new M-type streptococcal infectionMost common within first 5 years

Frequency decreases with time

GABH streptococcal pharyngitis

Age <15 years, high-grade fever, tonsillar

swelling/exudate, tender anterior Cxal LNE,

absence of cough

Treatment Acute streptococcal infection-

1.2 million units of benzathine penicillin G or amoxycillin/1st gen. oral cephalosporin x 10 days

Erythromycin, 500 BD x 10 days, if penicillin sensitive/allergic

Acute arthritis- ASA/NSAIDs Acute carditis- prednisolone, rest, diuretics, ACEI Chorea- diazepam, haloperidol, carbamazepine

Monitor ESR/CRP for duration of symptomatic Rx

Prophylaxis 1.2 million units of benzathine penicillin G,

IM q 3-4 weeks Sulfadiazine, 500 BD or Erythromycin, 250 BD,

if penicillin sensitive Duration- Without carditis- X 10 years or upto 21 years of age,

whichever is longer (WHO- x 5 yrs./upto 18 yrs. of age)

With carditis/RHD- upto 40 years of age (WHO- X 10 yrs./upto 25 yrs. of age)

Severe RHD/after valve Sx- lifelong Problem- compliance No recurrence with proper compliance