Epidemiology

Rheumatic heart disease (RHD) is steadily decreasing in the developed world in association with improved standards of living and the availability of penicillin. Amongst developing countries prevalence is variable, with one of the highest prevalences worldwide found in the indigenous Australian communities. A family history of ARF is common, reflecting genetic predisposition as well as environmental influences.

Pathophysiology

The exact pathogenesis of ARF remains unclear. It is postulated that certain virulent strains of Gram-positive Group A β-haemolytic streptococci (Streptococcus pyogenes) invade the pharynx, leading to the production of anti-streptococcal antibodies, which cross-react with host connective tissue.

History

Acute rheumatic fever usually presents in school-age children but may present at any age. A history of pharyngitis several weeks previously is found in 70% of older children, but younger children are less likely to recall a sore throat. Typically, ARF presents with up to a week of high fevers, followed by several weeks of milder temperatures and the appearance of a rash (erythema marginatum). Specific symptoms include migratory joint pain, chorea, and neuropsychiatric manifestations such as abrupt personality change or poor attention span. There may be symptoms of congestive heart failure or non-specific symptoms such as weight loss, fatigue, pallor, headache and abdominal pain.

Examination

The diagnosis of ARF relies upon the identification of specific clinical features. The National Heart Foundation of Australia has developed diagnostic criteria which depend on the stratification of patient risk (Table 5.6.1). High-risk groups are those who live in communities with high rates of ARF or RHD such as Aboriginal and Torres Strait Islanders.

Table 5.6.1 Diagnostic criteria for acute rheumatic fever

High-risk group All other individuals Major manifestations Carditis (including subclinical echocardiograph evidence)
Polyarthritis, aseptic monoarthritis, or polyarthralgia
Erythema marginatum
Subcutaneous nodules
Chorea Carditis (excluding subclinical echocardiograph evidence)
Polyarthritis
Erythema marginatum
Subcutaneous nodules
Chorea Minor manifestations Fever (documented >38°C)
ESR >30 mm hr^–1 or CRP >30 mg L^–1
Prolonged PR interval on ECG Fever (documented >38°C)
ESR >30 mm hr^–1 or CRP
>30 mg L^–1
Prolonged PR interval on ECG
Polyarthralgia or aseptic monoarthritis

Amended from National Heart Foundation of Australia; Diagnosis and management of acute rheumatic fever and rheumatic heart disease in Australia – an evidence-based review. 2006.

An initial episode of ARF may be diagnosed where two major or one major and two minor manifestations are present. The same criteria may be used to diagnose a recurrent episode, which otherwise requires the presence of three minor manifestations. All diagnoses require evidence of preceding Group A streptococcal (GAS) infection.