Ref: R Alagappan - Manual of Practical Medicine 4th Edition.pg no:146-147 Rheumatic Fever Acute, recurrent, inflammatory disease, mainly of children (aged 5-15 years), typically occurring 1-5 weeks after group A streptococcal infection. Pathophysiology 1. Cross reactivity of host antistreptococcal antibodies to cardiac antigens 2. Microbe initiated autoimmune reactivity. Jones Criteria for Diagnosis of Rheumatic Fever Major Criteria Carditis Pancarditis, seen in 50-60% of patients, develops within the first 2 weeks of rheumatic fever. Pericarditis is evidenced by presence of a pericardial rub, myocarditis by tachycardia, soft S1, presence of S3 and CCF and endocarditis by the presence of Carey-Coombs' murmur (mitral diastolic murmur). Ahritis (60-75%) Flitting and fleeting type of polyahritis involving large joints with no residual deformity is seen in 60-75% of patients and occurs early in rheumatic fever. Jaccod's ahritis: Ulnar detion of 4th and 5th finger with flexion at metacarpophalangeal joints is the only residual deformity seen in rheumatic polyahritis. Subcutaneous Nodules Non-tender nodules are seen over bony prominences like elbows, shin, occiput, spine in 3-5% of patients and occur 3-6 weeks after onset of rheumatic fever. Patients who have subcutaneous nodules almost always have carditis. Erythema Marginatum (< 5% and evanescent) Macular lesions with an erythematous rim and central clearing in a bathing suit distribution are seen in < 5% of patients and occur early in rheumatic fever. Chorea (Sydenham's Chorea) (2-30%) A neurological disorder with rapid, involuntary and purposeless non-repetitive movements with a self limiting course of 2-6 weeks is more common in females and is a late manifestation of rheumatic fever. Minor Criteria Clinical 1. Fever 2. Ahralgia 3. Previous history of rheumatic fever or rheumatic hea disease. Laboratory 1. Acute phase reactants (leucocytosis, raised ESR, C-reactive protein) 2. Prolonged PR interval in ECG (> 0.2 sec). WHO Criteria Jones major and pa of the minor criteria except prior history of rheumatic fever/rheumatic hea disease and C-reactive protein. Essential Criteria Evidence for recent streptococcal infection as evidenced by: 1. Increase in ASO titre a. > 333 Todd units (in children) b. > 250 Todd units (in adults). 2. Positive throat culture for streptococcal infection. 3. Recent history of scarlet fever. Two major (or) one major and two minor criteria, in the presence of essential criteria, is required to diagnose Acute Rheumatic Fever. A Positive Rheumatic Fever history is usually elicited in only 50% of patient with Rheumatic Hea Disease. Valve Involvement in Rheumatic Hea Disease Mitral valve alone 50% Aoic valve alone 15-20% Mitral and Aoic valves together 35-40% Mitral, Aoic and Tricuspid valves 2-3% Pulmonary valve is viually never involved. In RHD, mitral valve is most commonly involved followed by involvement of the aoic valve as the pressure gradient across the mitral valve is the greatest, followed by that across the aoic valve. So, the mitral valve is more susceptible to develop pathological changes than the aoic valve.