Acute Rheumatic Fever and Rheumatic Heart Disease

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49 Acute Rheumatic Fever and Rheumatic Heart Disease

Deepika Thacker, Amy L. Peterson

Acute rheumatic fever (ARF) is postulated to be caused by a delayed systemic autoimmune reaction to group A β-hemolytic streptococcal (GAS) pharyngitis. It is a self-limited disease that may involve the heart, skin, brain, joints, and serosal surfaces (Figure 49-1). It is a disease of clinical interest primarily because of its propensity to create heart disease. Rheumatic carditis and valvulitis may be self-limited or may lead to progressive valve deformity.

Figure 49-1 Cardiac manifestations of acute rheumatic fever.

Since the 1980s, the incidence of ARF has declined in most developed countries to the point where many physicians have little or no practical experience with diagnosis and management of the disease. Credit has been given to improved sanitation and widespread use of antibiotic therapy for GAS pharyngitis. Recently, however, several sporadic outbreaks have been reported in several regions of the United States, which have generally been attributed to new virulent strains of GAS.

In the United States, the incidence of ARF after untreated streptococcal pharyngitis is 0.5% to 3% with a peak frequency in children age 6 to 20 years. The disease is virtually unheard of in children younger than 2 years old and in adults older than 30 years old. The mean age of the first attack of ARF is 8 years. Internationally, however, rheumatic heart disease accounts for 25% to 50% of all cardiac admissions with most major outbreaks occurring in poverty-stricken, overcrowded areas with limited access to antibiotics.

Etiology And Pathogenesis

The exact cause of ARF and rheumatic heart disease (RHD) is unknown. ARF tends to occur after streptococcal pharyngitis rather than cellulitis. The familial tendency toward ARF is well documented. The HLA-DR2 and DR4 antigens have been linked to an increased incidence of ARF.

The virulence of GAS is related to the bacterial M protein, which structurally resembles human myosin. It is presumed that GAS adheres to the pharyngeal mucosa of the patient and activates antigens and superantigens, which triggers an immune response. In genetically susceptible individuals, antibodies against myosin are produced, which can lead to carditis. Repeated untreated infections with GAS may reactivate antibody production and lead to an autoimmune response that lasts several weeks and eventually damages heart valves (Figure 49-2).

Figure 49-2 Manifestations of acute rheumatic carditis.

Clinical Presentation

The diagnosis of ARF is challenging for several reasons. Pharyngitis is a common complaint in the pediatric population. About 70% of older children and young adults with ARF will recollect an antecedent pharyngitis, but only 20% of young children will. There is an average latent period from the onset of streptococcal pharyngitis to ARF of 18 days (range, 1-5 weeks), which can make recollection during the history challenging. Thus, GAS is rarely isolated from the oropharynx in patients with ARF. Typically, the first manifestation is a painful migratory polyarthritis, but 10% of rheumatic patients will present with pure chorea and no other manifestations of rheumatic fever.

More than 60 years ago, T. Duckett Jones published guidelines for diagnosis of ARF that have been slightly revised by the World Health Organization (Box 49-1 and Figure 49-3). To make a primary diagnosis of ARF, two major or one major and two minor criteria plus evidence of a preceding GAS infection are needed. The exception is rheumatic chorea. Sydenham’s chorea (St. Vitus dance) in isolation is considered diagnostic, and no other criteria or evidence of GAS infection are required to make the diagnosis.

Box 49-1 2002 to 2003 World Health Organization Revision of Jones Criteria for the Diagnosis of Rheumatic Fever

Major Criteria

1. Carditis: Murmur, irregular heartbeat, congestive heart failure. Murmur of mitral regurgitation is typically blowing, high frequency, and audible at the apex, and it transmits to the axilla. There may be a mid-diastolic rumble (Carey-Coombs murmur) that does not signify mitral stenosis. Heart rate irregularity can be noted with variable 2 : 1 block. A friction rub indicates pericarditis. CHF is rare, but patients may be very ill with dyspnea, vomiting, hepatomegaly, and tachycardia (see Figure 49-2).

2. Polyarthritis: Most commonly involved are hips, knees, ankles, shoulders, elbows, and wrists. It typically occurs in a migratory pattern and responds promptly to nonsteroidal antiinflammatory drugs or salicylates.

3. Erythema marginatum: Rapidly enlarging macules in ring or crescent shapes with clear centers. It is a rare manifestation but when present is very specific for ARF.

4. Subcutaneous nodules: Small, firm, nontender nodules over tendons and bony prominences that look similar to rheumatoid nodules. They are a rare manifestation.

5. Sydenham’s chorea: Involuntary choreoathetoid movements of the tongue, face, and upper extremities that are exacerbated by stress. It can occur as the sole manifestation of ARF. It is more common in girls than boys and is rare in adults.

Minor Criteria

1. Fever: Usually a low-grade fever, rarely higher than 103°F

2. Polyarthralgia

3. Laboratory evidence of elevated acute phase reactants: ESR, leukocyte count, or CRP

4. Prolonged PR interval on ECG)

Evidence of Preceding GAS Infection

1. Positive throat culture

2. Rapid antigen test for GAS

3. Recent scarlet fever

4. Elevated or rising ASO, anti-DNAse B, or other streptococcal antibody titer

anti-DNAse B, anti-deoxyribonuclease B; ARF, acute rheumatic fever; ASO, antistreptolysin O; CHF, congestive heart failure; CRP, C-reactive protein; ECG, electrocardiography; ESR, erythrocyte sedimentation rate; GAS, group A streptococcus.

Figure 49-3 Noncardiac manifestations of acute rheumatic fever.

Acute carditis is usually clinically manifest by sinus tachycardia without diurnal variation and new onset of a heart murmur of mitral regurgitation with or without aortic regurgitation. With a single attack of ARF, the mitral regurgitation often resolves over months to years, but aortic regurgitation is more likely to persist. In severe cases, signs of heart failure or a friction rub from pericarditis may also be present.

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