Rheumatic fever Medical Assignment Help

between 5 and 15 years of age) as a result of infection with group A streptococci. It affects the heart, skin, joints and central nervous system. It is common in the Middle and Far East, eastern Europe and South America, but it is now rare in the UK, western Europe and North America. This decline in the incidence of rheumatic fever (from 10% of children in the 1920s to 0.01% today) parallels the reduction in all streptococcal infections and is largely due to improved sanitation and also to the use of antibiotics. Pharyngeal infection with group A Streptococcus may be followed by the clinical syndrome of rheumatic fever. This is thought to develop because of an autoimmune reaction triggered by the infecting Streptococcus. The condition is not due to direct infection of the heart or to the production of a toxin.

PATHOLOGY

All three layers of the heart may be affected. The characteristic lesion of rheumatic carditis is the Aschoff nodule, which is a granulomatous lesion with a central necrotic area occurring in the myocardium, particularly in the subendocardium of the left ventricle. Small, warty vegetations may develop on the endocardium, particularly on the heart valves. This leads to some degree of valvular regurgitation. A serofibrinous effusion characterizes the acute pericarditis that occurs.
The synovial membranes are acutely inflamed during rheumatic fever, and subcutaneous nodules (which are also granulomatous lesions) are seen in the acute stage of the disease.

CLINICAL FEATURES

The disease presents suddenly, with fever, joint pains,malaise and loss of appetite. The clinical features depend  on the organs that are involved. Diagnosis relies on the presence of two or more major clinical manifestations or one major manifestation plus two or more minor features. These are known as the Duckett Jones criteria.
Carditis manifests as:
• New or changed heart murmurs
• Development of cardiac enlargement or cardiac failure
• Appearance of a pericardial effusion and EeG changes of pericarditis (raised ST segments) or myocarditis (inverted or flattened T waves), first-degree or greater AV block or other cardiac arrhythmias
• Transient diastolic mitral (Carey-Coombs) murmur due to mitral valvulitis
Non-cardiac features include the following .
A FEVER with an apparently excessive tachycardia is usually present.
THE ARTHRITIS ASSOCIATED WITH RHEUMATIC FEVER is classically a fleeting polyarthritis affecting large joints such as the knees, elbows, ankles and wrists. The joints are swollen, red and tender. As the inflammation in one joint recedes, another becomes affected. Once the acute inflammation disappears, the rheumatic process leaves the joints normal.
SYDENHAM’S CHOREA (or St Vitus’ dance) is involvement of the central nervous system that develops late after a streptococcal infection. Sufferers are noticeably ‘fidgety’ and display spasmodic, unintentional movements. Speech is often affected.
SKIN MANIFESTATIONS include erythema marginatum, a transient pink rash with -slightly raised edges, which occurs in 20% of cases. The erythematous areas found mostly on the trunk and limbs coalesce into crescentor ring-shaped patches. Subcutaneous nodules, which are painless, pea-sized, hard nodules beneath the skin, may also occur, particularly over tendons, joints and bony prominences.

Revised Duckett Jones criteria for the diagnosis

Revised Duckett Jones criteria for the diagnosis

INVESTIGATION

THROAT SWABS are cultured for the group A Streptococcus.
SEROLOGICAL CHANGES may indicate a recent streptococcal infection. The antistreptolysin 0 titre, and sometimes others such as the antistreptokinase titre, are performed.
NON-SPECIFIC INDICATORS OF INFLAMMATION such as the ESR and the C-reactive protein levels are usually elevated.

TREATMENT

Patients with fever, active arthritis or active carditis should be completely rested in bed. When the clinical syndrome has subsided (e.g. no pyrexia, normal pulse rate, normal ESR, normal white count) the patient may be mobilized.
Residual streptococcal infections should be eradicated with a single intramuscular injection of 916 mg of benzathine penicillin or oral phenoxyrnethylpenicillin 500 mg four times daily for 1 week. This therapy should be administered even if nasal or pharyngeal swabs do not culture the streptococci.
High-dose salicylate (preferably acetyl salicylate, i.e. aspirin) therapy is given to the limit of tolerance determined by the development of tinnitus. If carditis is present, systemic corticosteroids may be given. Prednisolone 60-120 mg in four divided doses each day is administered until the clinical syndrome is improved and the ESR has fallen to normal. Steroids are then tapered off over 2-4 weeks. However, the efficacy of steroids is in doubt. Recurrences are most common when persistent cardiac damage is present, and are prevented by the continued administration of oral phenoxymethylpenicillin 250 mg daily or by  monthly injections of 916 mg of benzathine penicillin until the age of 20 years or for 5 years after the latest attack (see p. 10). A sulphonamide (e.g. sulphadimidine) may be used if the patient is allergic to penicillin. Any streptococcal infection that does develop should be very promptly treated.

Chronic rheumatic heart disease

More than 50% of those who suffer acute rheumatic fever with carditis will later (after 10-20 years) develop chronic rheumatic valvular disease, predominantly affecting the mitral and aortic valves.

Posted by: brianna

Tags

Share This