ACUTE RHEUMATIC FEVER

Definition Current Diagnosis 07 An acute systemic immune disease that may develop after an infection with Group A beta- hemolytic Streptococcal infection of the pharynx. This disease can affect the HEART, JOINTS, SKIN, SUBCUTANEOUS TISSUE, BRAIN, RESPIRATORY SYSTEM, VESSELS, SEROSAL MEMBRANES, TENDONS AND FASCIAL SHEATHS

GENERAL CONSIDERATIONS Usually preceded – 2-3 weeks (1-5 weeks) by sore throat. Peak incidence years. Rare in 40 years 3% of pt dev ARF

PATHOLOGY The Aschoff bodies comprises a localised area of inflammation having a central deposit of amorphous fibrinoid material surrounded by an inflammatory infiltrate of mesenchymal cells known as Anitschkow giant cells or “caterpillar cells” (because the chromatin is distributed in the centre of the nucleus in the forrm of a slender wavy ribbon that resemles the attenuated body with innumerable fine leg like projections ) and an occasional multinucleated Aschoff giant cell with”owl eyed” nucleoli Fully developed Aschoff bodies are pathognomonic of RF Aschoff bodies proceed thru 3 phases- exudative, proliferative and healed

The heart has been sectioned to reveal the mitral valve as seen from above in the left atrium. The mitral valve demonstrates the typical "fish mouth" shape with chronic rheumatic scarring. Mitral valve is most often affected with rheumatic heart disease, followed by mitral and aortic together, then aortic alone, then mitral, aortic, and tricuspid together.

Microscopically, acute rheumatic carditis is marked by a peculiar form of granulomatous inflammation with so-called "Aschoff nodules" seen best in myocardium. These are centered in interstitium around vessels as shown here. The myocarditis may be severe enough to cause congestive heart failure.

Here is an Aschoff nodule at high magnification. The most characteristic component is the Aschoff giant cell. Several appear here as large cells with two or more nuclei that have prominent nucleoli. Scattered inflammatory cells accompany them and can be mononuclears or occasionally neutrophils.

Another peculiar cell seen with acute rheumatic carditis is the Anitschkow myocyte. This is a long, thin cell with an elongated nucleus.

MODIFIED JONES’ CRITERIA MAJOR: Polyarthritis Carditis Chorea Subcutaneous nodules Erythema marginatum

MINOR CRITERIA Clinical Fever Polyarthralgia h/o previous ARF or Rheum. heart disease Lab Reversible prolongation of PR interval Inc ESR Inc C Reactive Protein + throat culture Or rapid streptococcal antigen test Inc ASO titre

POLYARTHRITIS Migratory – flitting and fleeting Involves large joints sequentially Polyarthritis- in adults only a single joint may be affected Lasts 1-5 weeks Occurs in 75% or patients Subsides without residual deformity Dramatic response of arthritis to therapeutic doses of aspirin or NSAIDs

CARDITIS Most likely in children and adolescents Occurs in 1/3 of cases Any of the following signs suggest the presence of carditis 1.Endocardial- - MR or AR murmurs indicative of dilatation of valve ring with or without associated valvulitis -Short mid-diastolic murmur (Carey-Coombs) may be present - Changing quality of heart sounds 2. Myocardial - Tachycardia even at rest. Arrhythmias or ectopic beats - Cardiomegaly- on physical exam, CXR or ECHO - Congestive cardiac failure – right or left sided 3. Pericardial - Pericarditis - Pericardial effusion ECG Changes - Changing contour of P waves - Inversion of T waves - Prolongation of PR interval Maybe self limiting or may lead to slowly progressive valvular deformity Mitral valve attacked in 75% cases, aortic in 30% ( but rarely as the sole valve), tricuspid and pulmonary in < 5% cases

SYDENHAM’S CHOREA Involuntary choreo- athetoid movements primarily of the face, tongue, and upper extremities Maybe sole manifestation- in 50% of cases no other signs of RF Girls more frequenty affected Rare in adults Lease common(<3%) but most diagnostic of the manifestations of RF

Erythema Marginatum Rapidly enlarging macules that assume the shape of rings or crescents with clear centres They may be raised, confluent and either transient or persistent.

Subcutaneous Nodule Uncommon except in children Small (<2cm in diameter) firm & nontender Attached to fascia, or tendon sheaths over bony prominences Persist for days or weeks Are recurrent Indistinguishable from rheumatoid nodules

“Also there” features: Pneumonia Epistaxis Erythema nodosum Abdominal pain

REQUIRED FOR DIAGNOSIS Two major criteria OR One major and two minor criteria

DIFFERENTIAL DIAGNOSIS Rheumatoid arthritis Osteomyelitis Endocarditis Chronic meningiococcemia SLE Lyme disease Sickle cell disease Surgical abdomen

TREATMENT PHARYNGITIS Benzathene penicillin 1.2 million units ( 50,000 units/kg to a max of 1.2 million units) is injected IM once or Inj Procaine penicillin 600,000 units once daily for 10 days Erythromycin can be substituted ( 40mg/kg/day) CARDITIS Bed rest – until temp, ESR, resting pulse rate and ECG have all returned to normal Prednisone if there is CCF or cardiomegaly POLYARTHRITIS Anti inflammatory agent - Aspirin markedly reduces fever, joint pain and swelling No effect on the natural course of the disease 100mg / kg/day in 4-6 divided doses. Can be reduced to 75mg/Kg/day once there is a response. Given for 4-6 weeks Toxicity includes- tinnitus, vomiting and GI bleeding. When response to aspirin is inadequate a short course of prednisone (1 mg/kg/day) orally daily usually causes rapid improvement of joint symptoms. It is tapered over 2 weeks. Add aspirin when tapering begins.

PREVENON OF ARF-PRIMARY Early and adequate treatment of Strep. throat infections with a penicillin or Azithromycin will prevent Rheumatic Fever Avoidance of overcrowding & improved hygiene will decrease the incidence of pharyngitis

PREVENTION -SECONDARY Those who have had RF can have recurrences Recurrences are most common in children and in those patients who have had carditis during their initial episode of RF Recurrences are prevented by giving Benzathine penicillin 1.2million units IM every 4 week OR Oral penicillin 250 mg bid Erythromycin 250 mg bid Azithromycin Duration controversial: 5 years after last attack or at 25 years, whichever is later (earlier recommendation: life-long) Those with cardiac involvement and in high risk group- military personnel, health staff, school teachers, parents of young children- life long prophylaxis

RHEUMATIC HEART DISEASE Results from single or repeated attacks of RF Rigidity and deformity of valves resulting in stenosis or incompetence or both Mitral valve alone in 50% Mitral + Aortic in 25% Pure aortic uncommon History of RF obtained in 60% Should receive prophylatic penicillin monthlyand preceding dental extractions,urologic and surgical procedures to prevent endocarditis