Rheumatic fever is an auto-immune disease of childhood and commonest cause of acquired heart disease. It is characterized by lesions in the heart, blood vessels, joints and other connective tissues. It bites the heart and leaks the joints.
Etiology:
It is generally accepted that rheumatic fever is causally related to infection by the Group-A beta-hemolytic Streptococcus, although this organism cannot be recovered from the rheumatic lesions themselves. It is thought that some kind of antigen-antibody reaction is involved in the pathogenesis of rheumatic fever.
Clinical features:
It occurs in children from 5 to 15 years of age, with a marked predominance in lower socio-economic groups.Two major criteria or one major and two minor criteria plus evidence of a preceding streptococcal infection indicate a high probability of rheumatic fever.
In the three special categories listed below, the diagnosis of rheumatic fever is acceptable without two major or one major and two minor criteria. However, only for a and b (also given below as image) can the requirement for evidence of a preceding streptococcal infection be ignore. (Modified from American Heart Association and World Health Organization):
a. Chorea: If other causes have been excluded.
b. Insidious or late-onset carditis: With no other explanation
c. Rheumatic recurrence: In patients with documented rheumatic heart disease, the presence of one criteria or of fever, arthralgia, or elevated acute-phase reactants suggest a presumptive diagnosis of recurrence.Evidence of previous streptococcal infection is needed here.
Features of the Disease:
Major criteria. The five major criteria are considered to be the most specific findings; therefore, more weight is given to major criteria.
Carditis:
Carditis is present in 40 to 80 % of patients with rheumatic fever. It is evidenced by any of the following:
a. The presence of a significant apical systolic, apical mid-diastolic or basal diastolic murmur in an individual without a previous history of rheumatic fever.
b. Cardiomegaly with or without heart failure.
c. Evidence of pericarditis and pericardial effusion.
d. Congestive cardiac failure in the absence of other causes.
e. Tachycardia.
f. Arrhythmias(usually Ist degree heart block,but 3rd-degree or complete heart block may occur).
Polyarthritis:
Polyarthritis is 'flitting or migratory in nature. There is limitation of active movement by swelling and pain in big joints. Following initiation of anti-inflammatory therapy, the arthritis may literally disappear in 12 to 24 hour. Untreated, it may persist for a week or more.
Chorea:
Rheumatic chorea must be differentiated from habitual spasms, athetosis and cerebellar ataxia. Chorea can occur in association with other manifestations such as arthritis and carditis, but it frequently appears as a solitary and rather odd phenomenon. It is more common in girls. Characteristic features of the chorea are:
a. Involuntary, purposeless, non-repetitive movements of the limbs, face and trunk; e.g. grimacing, wriggling and writhing. The movements can be brought under voluntary control temporarily, are aggravated by excitement and may disappear during sleep.
b. Hypotonia which may result in muscular weakness and the characteristic posture of the outstretched hand in which the wrist is flexed and the metacarpo-phalangeal joints are hyper extended.
c. In coordination which may be marked.
d. Mental upset with emotional ability.This is almost universal, with deterioration in school work.
Erythema Marginatum:
Erythema marginatum typically has a map-like, well defined erythematous margins and white centres, and changes shape continually over the course of the illness. It is pathognomonic of rheumatic fever. It is very rarely seen in dark-skinned children.
Subcutaneous Nodules:
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These are small and firm,and are most often found over bony prominences and in tendon sheaths.
Minor criteria:
The minor manifestations are much less specific but are necessary to confirm a diagnosis of rheumatic fever. Arthralgia is present if the patient feels discomfort in the joint in the absence of objective findings (pain, redness, warmth) on physical examination. (Arthralgia can not be counted in satisfying the Jones criteria if arthritis is present). Fever, usually no higher than 101° or 102° F. Previous history of documented rheumatic fever may be present. Acute phase reactants may be elevated and remain elevated for prolonged periods of time (months). A prolonged P-R interval on the electrocardiogram is also included among the minor criteria.
Evidence of preceding Streptococcal infection:
This is one of the most important aspects of the Jones Criteria. This includes:
a. History of recent scarlet fever
b. Positive throat culture for group A -hemolytic Streptococcus
c. Specific antibody tests:
i. Elevated antistreptolysin O (ASO) titre
ii. Anti DNase B (Antideoxyribo neuclease B), anti NA Dase ( anti nicotinamide adenine dinucleotidase), anti hyaluronidase (AH) and anti streptokinase is elevated.
Approximately 80% of individuals with rheumatic fever have an elevated ASO titre and an elevation of at least one antibody will be found in more than 95% of patients with rheumatic fever.
Treatment and management:
1. Bed rest is the single most important therapeutic measure in rheumatic fever or chorea. Patient should be examined daily to detect carditis which almost always appears within 2 weeks of onset.
Guidelines :
i) Patients with no carditis require bed rest for 2 weeks and gradual ambulation for 2 weeks.
ii) Patients having carditis but no enlargement require bed rest for 4 weeks and gradual ambulation for 4 weeks.
iii) Patients with carditis with enlargement need bed rest for 6 weeks and gradual ambulation for 6 weeks.
iv) Patients having carditis with heart failure need strict bed rest for as long as heart failure is present and gradual ambulation for 3 months.
2. Salicylates cause dramatic improvement by lowering fever, pain and swelling of joints. Very mild carditis without evidence of congestive heart failure, salicylates alone are indicated. The dose is 90-120 mg/kg/day in 4 divided doses which maintains a blood salicylate level of 20-25 mg/dl (2.17-2.9 mol).Antacids should be given prior to salicylate administration to minimize gastric erosion. Reduce the dose to one third after fever and joint pain have subsided and continue until the ESR is normal.
3. The role of corticosteroids in rheumatic fever remains controversial. They undoubtedly lead to more rapid relief, and a more rapid fall in ESR (Massell 1954) than aspirin.Definite indications for corticosteroids in rheumatic fever are moderate to severe carditis with congestive cardiac failure and relapses.
Corticosteroids are helpful in controlling the acute inflammatory process but do not modify the incidence or severity of chronic rheumatic heart disease. Prednisolone 2 mg/kg/day in 4 divided doses is given for 7 to 10 days, then the dose is reduced to 1 mg/kg/day for 2 to 3 weeks. It is further slowly decreased to zero over the next 7 to 14 days. The salicylates should be given during the last week of corticosteroid therapy and continued for approximately 3 to 4 weeks after the steroid have been discontinued.
4. Congestive heart failure should he treated by conventional technique. Diuretics are indicated in patients with severe congestive heart failure.Cardiac glycosides such as digitalis also may he used, although usually in relatively small doses.
5. Diazepam, benzodiazepine derivatives: has been prescribed for patients with mild chorea. In patients with severe chorea, haloperidol has been used successfully.
6. Penicillin therapy is a must, to eradicate Streptococcal infection.It can be administered according to any of the following regimens:
a. Procaine penicillin 400,000 units IM daily for 2 weeks
b. Phenoxymethyl penicillin 250 mg every 6 hours for 2 weeks
c. In cases of hypersensitivity to penicillin, erythromycin may be used for 2 weeks.
Prophylaxis:
This is aimed at preventing further Streptococcal infections. For this purpose, administration of 1.2 mega units of long acting penicillin, benzathine penicillin G IM every 3 to 4 weeks is the universal recommendation. Sulfadiazine 500 mg twice daily or oral phenoxymethyl penicillin 250 mg twice daily may also be used as prophylaxis. If penicillin hypersensitivity exists, erythromycin 125-250 mg orally daily is of value. Every precaution must be taken during tooth extraction or any instrumental procedure.Prophylaxis should be continued for at least 5 years after the last attack or until the age of 18 years.
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