Rheumatic Fever: Etiology, Epidemiology, Pathogenesis, Clinical Manifestations, Diagnosis, Treatment, Prevention, Progno

1. Rheumatic Fever Dr.M.H.Jokar www.doctorjokar.com

2. Objectives • Etiology • Epidemiology • Pathogenesis • Clinical manifestations & Laboratory findings • Diagnosis & Differential diagnosis • Treatment & Prevention • Prognosis

3. DEFINITION Acute rheumatic fever (ARF) is a systemic autoimmune disease triggered by cross-reactive immune responses between group A β-hemolytic streptococci (GAS) and host tissue epitopes.

4. “The most important consequence of rheumatic fever is chronic rheumatic heart disease”

5. Epidemiology • Ages 5-15 yrs are most susceptible • Rare <3 yrs • Girls=boys • Common in 3rd world countries • Environmental factors-- over crowding, poor sanitation, poverty, • Incidence more during fall ,winter & early spring

6. Epidemiology • 3% of individuals with untreated group A streptococcal pharyngitis will develop rheumatic fever

7. Epidemiology

9. Pathophysiology

10. Etiology • Follows group A beta hemolytic streptococcal pharyngitis • It is a delayed non-suppurative sequelae to URTI with GABH streptococci.

11. Diagrammatic structure of the group A beta hemolytic streptococcus Antigen of outer protein cell wall of GABHS induces antibody response in victim which result in autoimmune damage to heart valves, sub cutaneous tissue,tendons, joints & basal ganglia of brain Capsule Cell wall Proteinantigens Group carbohydrate Peptidoglycan Cyto.membrane Cytoplasm …………………………………………………...

12. Strains that produces rheumatic fever - M types l, 3, 5, 6,18 & 24 Pharyngitis- produced by GABHS can lead to- acute rheumatic fever , rheumatic heart disease & post strept. Glomerulonepritis Skin infection- produced by GABHS leads to post streptococcal glomerulo nephritis only. It will not result in Rh.Fever or carditis as skin lipid cholesterol inhibit antigenicity Group A Beta Hemolytic Streptococcus

13. Tonsillitis

14. Pathogenesis Abnormal immune response to one or more as yet unidentified somatic or extracellular antigens produced by all (or perhaps only by some) group A streptococci.

15. Pathogenesis • Delayed immune response to infection with group.A beta hemolytic streptococci. • After a latent period of 1-3 weeks, antibody induced immunological damage occur toheart valves,joints, subcutaneous tissue & basal ganglia of brain

16. Pathogenesis • Antigenic mimicry • Predisposing genetic influence

19. Arthritis • Migratory polyarthritis, involving large joints: knee,ankle,elbow & wrist • Occur in 80% • Involved joints are exquisitely tender • In children below 5 yrs arthritis usually mild but carditis more prominent • Arthritis do not progress to chronic disease

20. It usually does not affect the small joints of the hands or feet and seldom involves the hip joints

22. Carditis

23. Occur in 5-10% of cases Mainly in girls of 5-15 yrs age May appear even 6/12 month after the attack of rheumatic fever Clinically manifest as deterioration of handwriting, emotional lability or grimacing of face Clinical signs- milking sign of hands Sydenham Chorea

25. 4.Erythema Marginatum • Occur in <5%. • Unique,transient,serpiginous-looking lesions of 1-2 inches in size • Pale center with red irregular margin • More on trunks & limbs & non-itchy • Worsens with application of heat • Often associated with chronic carditis

27. Subcutaneous nodules • Occur in 5-10% • Painless,pea-sized,palpable nodules • Mainly over extensor surfaces of joints,spine,scapulae & scalp • Always associated with severe carditis

28. SUBCUTANEOUS NODULES

29. Other features (Minor features) • Fever • Arthralgia • Pallor • Anorexia • Loss of weight

30. Laboratory Findings • High ESR • Anemia, leucocytosis • Elevated C-reactive protien • ASO titre >200 Todd units.80% (Peak value attained at 3 weeks,then comes down to normal by 6 weeks) • Anti-DNAse • Throat culture-GABHstreptococci 20-40%

31. Pathology Aschoff nodule (body)

32. درس فيزيوپاتولوژی

33. Diagnosis • Rheumatic fever is mainly a clinical diagnosis • No single diagnostic sign or specific laboratory test available for diagnosis

34. Major & Minor manifestations Major • Carditis • Polyarthritis • Chorea • Erythema marginatum, • Subcutaneous nodules. Minor • Fever • Polyarthralgia • Acute-phase reactants (erythrocyte sedimentation rate or leukocyte count).

35. Supporting evidence for a preceding GAS • Prolonged PR interval • Elevated or rising aso or antibody • Positive throat culture • Positive rapid antigen test • Recent scarlet fever.

37. DIFFERENTIAL DIAGNOSIS

38. Treatment • Step I- primary prevention (eradication of streptococci) • Step II- anti inflammatory treatment (aspirin,steroids) • Step III- secondary prevention (prevention of recurrent attacks)

39. ANTI-INFLAMMATORY AGENTS Aspirin 4-8grams/day for adults Continue anti-inflammatory therapy until ESR or CRP are normal May need steroids if there is cardiac involvement to help prevent sequelae such as mitral stenosis Corticosteroids, if indicated, are given at prednisone 2mg/kg/day for 2 weeks and then tapered

41. Prognosis • Rheumatic fever can recur whenever the individual experience new GABH streptococcal infection,if not on prophylactic medicines • Good prognosis for older age group & if no carditis during the initial attack • Bad prognosis for younger children & those with carditis with valvar lesions