9. Rheumatic Fever.pptx,______________::::::::

Rheumatic fever

1. CARDIOLOGY Cardiology lecture 8 :- Rheumatic Fever Date:- 13/12/2020 Prepared by Dr Guled Mohamud Nur (GMN@N ) MBBS

2. Rheumatic fever

3. Overview Acute rheumatic fever ( ARF ) results from an autoimmune response to infection with group A streptococcus . Rheumatic fever is an acute, inflammatory disease principally of children but also of adults that usually follows a pharyngeal infection with group A beta-hemolytic streptococcus after a latent period of approximately 3 weeks . Most likely it is the result of cross-reaction between the body immune response to streptococcal antigens and tissue antigens , principally in the heart.

4. Aetiology Infections of the pharynx with group A beta- haemolytic streptococci ( GAS ) are the precipitating cause of rheumatic fever. Streptococcal skin infections (impetigo or pyoderma) have not been proven to lead to acute rheumatic fever, Organs involved include:- connective tissue of heart, joints, skin, blood vessels and lungs.

5. Epidemiology In developing areas of the world, acute rheumatic fever and rheumatic heart disease are estimated to affect nearly 20 million people, with an incidence exceeding 50 per 100 000 children . Improved economic standards, better housing condition, decreased crowding in homes and schools and use of antibiotics and proper treatment of pharyngitis markedly declined rheumatic fever in advanced countries.

6. Pathophysiology The autoimmune response that causes ARF is supposed to be triggered by molecular mimicry between epitopes on the pathogen (group A streptococcus ) and specific human tissues . The structural and immunological similarities between streptococcal M protein and myosin are essential to the development of rheumatic carditis. The initial damage to the valve might be due to laminin that is present in the valvular basement membrane and around endothelium, and which is recognized by T cells against myosin and M protein .

7. Clinical forms The main features of ARF are described in the modified Jones criteria , as presented, together with the WHO criteria. Carditis , associated with a murmur of valvulitis , occurs in 50–70% of patients and is the most specific manifestation of ARF . Polyarthritis is the most common , but least specific, major manifestation. The classic migratory polyarthritis of the major joints of rheumatic fever should be distinguished from the post-streptococcal reactive arthritis of the small joints of the hand that does not carry a risk of carditis.

8. Clinical forms Chorea (Sydenham’s chorea, St. Vitus dance, or chorea minor) occurs in about 20% of cases. It is a delayed manifestation of ARF , usually appearing ≥ 3 months after the onset of the precipitating streptococcal infection. Erythema marginatum and subcutaneous nodules in the elbows, knees, and the occipital portion of the scalp are rare (<5%).

9. Jones criteria Two major or one major and two minor manifestations must be present, plus evidence of antecedent group A Streptococcus infection. Recurrent episode requires only one major or several minor manifestations , plus evidence of antecedent group A Streptococcus infection

10. Major manifestations Carditis Polyarthritis Chorea Erythema marginatum Subcutaneous nodules

11. Minor manifestations Arthralgia Fever Raised erythrocyte sedimentation rate or C-reactive protein concentrations Prolonged PR interval on electrocardiogram Evidence of antecedent group A Streptococcus infection Positive throat culture or rapid antigen test for group A Streptococcus Raised or rising streptococcal antibody titre

12. Investigations Although the diagnosis of rheumatic fever is clinical, following investigations may be helpful. Throat swab culture Throat swab culture for group A streptococci Anti-streptolysin O titer (ASOT) The rising titer of antibodies against streptococci (ASOT) indicates a recent streptococci infection. ASOT is elevated in about 80% of cases.

13. Investigations ESR and C-reactive protein Are the acute phase reactants indicating tissue inflammation and are elevated during the acute stage of the disease. Blood CP Leukocytosis with TLC 12000-15000mm may be observed in acute stage of RF. Anemia is usually mild to moderate and is normocytic, normochromic in morphology.

14. Investigations Chest x ray May be normal, or indicates cardiomegaly and pulmonary edema. ECG May indicate prolonged PR interval, heart block, features pericarditis and myocarditis. Echocardiography It may show mitral regurgitation due to prolapse of anterior mitral leaflet, heart dilatation and valve abnormality.

15. Treatment Complete bed rest Patient should be kept at strict bed rest until, The temperature returns to normal ESR returns to normal Resting pulse rate normal ECG returns to baseline.

16. Treatment Salicylates Salicylates ( aspirin ) markedly reduces fever and relieves joint pain and swelling. Its given as 100mg / kg / day in 4-5 divided doses. After the polyarthritis has been controlled successfully for 2 weeks, the aspirin dosage should be tapered for an additional 6 weeks.

17. Treatment Corticosteroids A short course of corticosteroids ( prednisolone 40-80mg / day for 2 weeks , after which the dosage is tapered slowly over 3 weeks usually causes rapid improvement and indicated when response to salicylate has been inadequate or there is severe arthritis or carditis accompanied by congestive heart failure.

18. Primary prevention of rheumatic fever (treatment of streptococcal tonsillopharyngitis)

19. Penicillins Penicillin V ( phenoxymethyl penicillin) Children: 250 mg 2–3 times daily for ≤ 27 kg (60 lb ); children >27 kg (60 lb ), adolescents, and adults: 500 mg 2–3 times daily Oral 10 days, or Amoxicillin 50 mg/kg once daily (maximum 1 g) Oral 10 days Benzathine penicillin G 600 000 U for patients ≤ 27 kg (60 lb ); 200 000 U for patients >27 kg (60 lb ) Intramuscular Once

20. For individuals allergic to penicillin Narrow-spectrum cephalosporin (cephalexin, cefadroxil) Oral 10 days, or Clindamycin 20 mg/kg per day divided in three doses (maximum 1.8 g/d) Oral 10 days Azithromycin 12 mg/kg once daily (maximum 500 mg) Oral 5 days, or Clarithromycin 15 mg/kg per day divided bd (maximum 250 mg bd) Oral 10 days.

21. Secondary prevention of rheumatic fever (prevention of recurrent attacks)

22. Penicillin Benzathine penicillin G 600 000 U for children ≤ 27 kg (60 lb ), 1 200 000 U for those >27 kg (60 lb ) every 4 wk * 250 mg twice daily. Penicillin V Oral Sulfadiazine 0.5 g once daily for patients ≤ 27 kg (60 lb ), 1.0 g once daily for patients >27 kg (60 lb ) Oral. For individuals allergic to penicillin and sulfadiazine Macrolide or azalide Variable Oral

23. Complications Congestive heart failure Rheumatic heart disease Arrhythmias Pericarditis Pericardial effusion Rheumatic pneumonitis

24. Chronic rheumatic heart disease Chronic rheumatic heart disease result from single or repeated attacks of rheumatic fever that produce rigidity and deformity of valve cusps, fusion of the chordae tendinae , leading to stenosis or regurgitation.

25. Reference By Clinical Cardiology Current Practice Guidelines And Short textbook of medical diagnosis & treatment. 11 th Edition