Acute rheumatic fever is an immune-mediated condition triggered by group A streptococcal infection, usually pharyngitis or tonsillitis. It is caused by antibodies produced against streptococcal bacteria that also target tissues in the body.
It is a multi-system disorder that affects the joints, heart, skin and nervous system. It is rare in the UK due to early treatment of streptococcal infections with antibiotics.
Pathophysiology
Rheumatic fever is caused by group A beta-haemolytic streptococci, typically Streptococcus pyogenes, causing tonsillitis or pharyngitis. The immune system creates antibodies to fight the infection. These antibodies not only target bacteria but also bind to antigens on the body’s cells, such as muscle cells in the heart’s myocardium, activating the immune system.
This results in a type 2 hypersensitivity reaction, in which the immune system attacks cells throughout the body. There is usually a 2-4-week delay between the initial infection and the onset of rheumatic fever.
Presentation
The typical presentation of rheumatic fever occurs 2-4 weeks following a streptococcal infection, such as tonsillitis. Symptoms affect multiple systems, causing:
- Fever
- Joint pain
- Rash (erythema marginatum)
- Shortness of breath
- Chorea
- Nodules
Rheumatic fever causes a migratory arthritis affecting the large joints. It causes hot, swollen and painful joints. Different joints become inflamed and improve at different times, giving the appearance that the arthritis is moving from one joint to the next.
Pericarditis, myocarditis and endocarditis can lead to:
- Tachycardia
- Murmurs due to valvular heart disease, typically mitral valve disease
- Pericardial rub on auscultation
- Heart failure
There are two key skin findings with rheumatic fever:
- Subcutaneous nodules over extensor surfaces of joints, such as the elbows
- Erythema marginatum rash, involving pink rings of varying sizes affecting the torso and proximal limbs
Chorea is the key nervous system symptom, and involves irregular, uncontrolled and rapid movements of the limbs. This is also known as Sydenham chorea and historically was called St Vitus’ dance.
Assessment
Investigations to support the diagnosis include:
- Throat swab for bacterial culture
- Blood sample for ASO antibody titres
- Echocardiogram, ECG and chest x-ray to assess for heart involvement
A diagnosis of rheumatic fever is made using the Jones criteria.
Anti-Streptolysin O Titres
Anti-streptolysin O (ASO) are antibodies against streptolysin O, a toxin produced by group A strep. They indicate a recent streptococcal infection and can help support a diagnosis of rheumatic fever. After an acute infection, the levels usually:
- Rise over 2-4 weeks
- Peak around 3-6 weeks
- Gradually fall over 3-12 months
ASO levels are usually repeated after 2 weeks to identify a rising level.
Anti-DNase B (anti-Streptodornase B) is another marker of recent group A strep infection, often used when ASO titres are negative.
Jones Criteria
A diagnosis of rheumatic fever can be made when there is evidence of recent streptococcal infection, plus:
- Two major criteria OR
- One major criterion plus two minor criteria
The mnemonic for the Jones criteria is JONES – FEAR.
Major Criteria
- J – Joint arthritis
- O – Organ inflammation (specifically carditis)
- N – Nodules
- E – Erythema marginatum rash
- S – Sydenham chorea
Minor Criteria
- Fever
- ECG changes (prolonged PR interval) without carditis
- Arthralgia without arthritis
- Raised inflammatory markers (CRP and ESR)
Management
Treatment of streptococcal infections with antibiotics helps prevent the development of rheumatic fever. Tonsillitis caused by streptococcus is treated with phenoxymethylpenicillin (penicillin V) for 5-10 days.
Patients with features of rheumatic fever are referred for urgent specialist assessment.
Management involves medications and follow-up:
- NSAIDs (e.g., ibuprofen) or aspirin are used for arthritis and fever
- Corticosteroids may be used to treat carditis (inflammation of the heart)
- Antibiotics (e.g., oral or intramuscular penicillin) are used to treat and prevent further streptococcal infections
- Monitoring and management of complications
TOM TIP: In a child with previous rheumatic fever, further exposure to the strep bacteria can result in the immune system producing the antibodies that cause rheumatic fever, resulting in a recurrence of the disease. Long-term prophylactic penicillin is used to kill streptococcal bacteria before they can stimulate the immune system, reducing the risk of recurrence.
Last updated August 2026
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