'Rheumatic fever' is an
inflammatory disease which may develop after a
Group A streptococcal infection (such as
strep throat or
scarlet fever) and can involve the
heart,
joints,
skin, and
brain.
General information
Rheumatic fever is common worldwide and is responsible for many cases of damaged
heart valves. In the Western countries, it became fairly rare since the 1960s, probably due to widespread use of antibiotics to treat
streptococcus infections. While it is far less common in the
United States since the beginning of the
20th century, there have been a few outbreaks since the
1980s. Although the disease seldom occurs, it is serious and has a mortality of 2–5%.
Rheumatic fever primarily affects children between ages 6 and 15 years and occurs approximately 20 days after strep throat or scarlet fever. In up to a third of cases, the underlying strep infection may not have caused any symptoms.
The rate of development of rheumatic fever in individuals with untreated strep infection is estimated to be 3%. The rate of development is far lower in individuals who have received antibiotic treatment. Persons who have suffered a case of rheumatic fever have a tendency to develop flare-ups with repeated strep infections.
The recurrence of rheumatic fever is relatively common in the absence of maintenance of low dose antibiotics, especially during the first three to five years after the first episode of rheumatic fever. Heart complications may be long-term and severe, particularly if the heart valves are involved.
Diagnosis: modified Jones criteria
T. Duckett Jones, MD, first published these criteria in 1944.
[1] They have been periodically revised by the
American Heart Association in collaboration with other groups.
[2] 'Two major criteria, or one major and two minor criteria', when there is also evidence of a previous strep infection, support the diagnosis of rheumatic fever.
[3][4]
Major criteria
★ 'Carditis:' inflammation of the heart muscle which can manifest as
congestive heart failure with shortness of breath,
pericarditis with a rub, or a new
heart murmur.
★ '
Migratory polyarthritis:' a temporary migrating inflammation of the large joints, usually starting in the legs and migrating upwards.
★ '
Sydenham's chorea (St. Vitus' dance):' a characteristic series of rapid movements without purpose of the face and arms. This can occur very late in the disease.
★ '
Erythema marginatum:' a long lasting rash that begins on the trunk or arms as
macules and spread outward to form a snakelike ring while clearing in the middle. This rash never starts on the face and is made worse with heat.
★ 'Subcutaneous nodules (a form of
Aschoff bodies):' painless, firm collections of collagen fibers on the back of the wrist, the outside elbow, and the front of the knees. These now occur infrequently.
Minor criteria
★ '
Fever': temperature elevation
★ '
Arthralgia:' Joint pain without swelling
★ 'Laboratory abnormalities:' increased
Erythrocyte sedimentation rate, increased
C reactive protein,
leukocytosis
★ '
Electrocardiogram' abnormalities: a prolonged PR interval
★ 'Evidence of Group A Strep infection:' positive culture for Group A Strep, elevated or rising
Antistreptolysin O titre
★ 'Previous rheumatic fever or inactive heart disease'
Other signs and symptoms
★
Abdominal pain
★
Nosebleeds
Pathophysiology
Rheumatic fever is a systemic disease affecting the peri-arteriolar connective tissue and can occur after an untreated Group A streptococcal pharyngeal infection. It is believed to be caused by antibody
cross-reactivity. This cross-reactivity is a Type II hypersensitivity reaction and is termed ''molecular mimicry.'' Usually self reactive B cells remains anergic in the periphery without T cell costimulation. During a Strep infection activated antigen presenting cells (such as a macrophage) present the bacterial antigen to helper T cells. Helper T cells will subsequently activate B cell and induce the production of antibodies against the cell wall of Streptococcus. However the antibodies can also react against the myocardium and joints
[5] and producing the symptoms of Rheumatic fever.
Group A ''
streptococcus pyogenes'' has a
cell wall that is composed of branched
polymers which sometimes contain "''M proteins''" that are highly
antigenic. The antibodies the immune system generates against the "''M proteins''" may cross react with cardiac myofiber
sarcolemma and smooth muscle cells of arteries, inducing
cytokine release and tissue destruction. This inflammation occurs through direct attachment of complement and Fc receptor-mediated recruitment of neutrophils and macrophages. Characteristic Aschoff bodies, composed of swollen eosinophilic collagen surrounded by lymphocytes and macrophages can be seen on light microscopy. The larger macrophages may become Aschoff giant cells. Acute rheumatic valvular lesions may also involve a
cell-mediated immunity reaction as these lesions predominantly contain
T-helper cells and
macrophages.
[6]
In acute RF, these lesions can be found in any layer of the heart and is hence called pancarditis. The inflammation may cause a serofibrinous pericardial exudates described as “bread-and-butter” pericarditis, which generally resolves without sequelae. Involvement of the endocardium typically results in fibrinoid necrosis and verrucae formation along the lines of closure of the left-sided heart valves. Warty projections arise from the deposition, while subendothelial lesions may induce irregular thickenings called MacCallum plaques.
Chronic rheumatic heart disease is characterized by repeated inflammation with fibrinous resolution. The cardinal anatomic changes of the valve include leaflet thickening, commissural fusion and shortening and thickening of the tendinous cords. RHD cause 99% of mitral stenosis often resulting in a “fish mouth” gross appearance.
[7]
Treatment
The management of acute rheumatic fever is geared toward the reduction of inflammation with
anti-inflammatory medications such as
aspirin or
corticosteroids. Individuals with positive cultures for strep throat should also be treated with
antibiotics. Another important cornerstone in treating rheumatic fever includes the continuous use of low dose antibiotics (such as
penicillin,
sulfadiazine, or
erythromycin) to prevent recurrence.
Infection
Patients with positive cultures for ''streptococcus pyogenes'' should be treated with penicillin as long as
allergy is not present. This treatment will not alter the course of the acute disease.
Inflammation
Patients with significant symptoms may require
corticosteroids.
Salicylates are useful for pain.
Heart failure
Some patients develop significant
carditis which manifests as
congestive heart failure. This requires the usual treatment for heart failure:
diuretics,
digoxin,
etcetera. Unlike normal heart failure, rheumatic heart failure responds well to
corticosteroids.
Prevention
Prevention of recurrence is achieved by eradicating the acute infection and
prophylaxis with antibiotics. The
American Heart Association recommends prophylaxis continue at least 10 years.
Nurses also have a role in prevention, primarily in screening school-aged children for sore throats that may be caused by Group A streptococci(especially Group A β Hemolytic Streptococcus pyogenes).
References
1. Jones TD. The diagnosis of rheumatic fever. ''JAMA''. 1944; 126:481–484
2. Ferrieri P. Proceedings of the Jones criteria workshop. ''Circulation'' 2002; 106 : 2521–23
3. eMedicine - Rheumatic Fever : Article by Steven J Parrillo, DO, FACOEP, FACEP
4. Guidelines for the diagnosis of rheumatic fever. Jones Criteria, 1992 update. Special Writing Group of the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young of the American Heart Association, , , , JAMA, 1992
5. Abbas and Lechtman. 'Basic Immunology: Functions and Disorders of the Immune System'. Elsevier Inc. 2004.
6. Kumar et al. 'Robbins and Cotran Pathologic Basis of Disease'. Elsevier Inc. 2005
7. Robbins & Cotran Pathologic Basis of Disease
External links
★
Rheumatic fever information from Seattle Children's Hospital Heart Center
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