Acute Rheumatic Fever
Acute Rheumatic Fever - ARF is an auto-immune reaction which follows Group A streptococcus infection with multisystem involvement of heart, joints, brain and skin. Arthritis tends to occur early and is often migratory (sometimes called 'flitting' as it moves from joint to joint), tends to affect large joints (often legs first). Arthritis can affect a single joint and ARF must be considered. Rheumatic heart disease is a serious complication with high morbidity and mortality. Treatment of ARF is with prolonged antibiotics and management of organ involvement such as heart failure from carditis or valvular disease. Neurological complications include chorea (erratic limb movements from extrapyramidal involvement).
Features suggestive of Acute Rheumatic Fever include:
- Joint pain and swelling primarily affecting large joints, particularly knees, ankles, wrists and elbows. A monoarthritis is also a recognised presentation. Usually initially one joint is affected and is migratory (i.e., moves to affect other joints) and additive (i.e., one to several joints affected). Joint pain is prominent, occurs at rest and is increased by movement.
- Associated manifestations may include systemic features (fever, malaise, abdominal pain, vomiting), carditis (signs ranging from tachycardia at rest, prolonged PR interval, new murmur suggesting mitral and/or aortic insufficiency to acute heart failure), erythema marginatum skin rash (non-pruritic, macular, serpiginous rash with erythematous border especially on trunk and upper, inner aspects of limbs), neurological features with irritability, headaches, Sydenham chorea (usually symmetric persistent, involuntary and purposeless movements of extremities - please see the video demonstration of chorea), subcutaneous nodules (extensor surfaces, but rare) or evidence of nephritis (microscopic haematuria, pyuria).
- The diagnosis is made using the Jones criteria (revised 2015) - see Further Reading.
- Evidence of streptococcal infection (streptococcal serology or throat swab positive for group A streptococcus); there may be a history of sore throat before the onset of joint pains.
- More information about ARF is provided in clinical assessment, investigations and arthritis modules.
ARF is important due to cardiac and neurologic complications and sequelae. The prevalence of ARF varies around the world and some countries (such as in India) are observing declining numbers of presentations of ARF which is also reflected in reducing numbers of patients requiring valvular heart surgery in the major cardiac centres. In other parts of the world, e.g., New Zealand, high rates of ARF are still seen in Maori and Pacific children and young adults.
The diagnosis of ARF is established largely on clinical grounds using the "Jones criteria" (Major and Minor criteria). These have been revised in 2015 (see Further Reading below). Major criteria include carditis (including subclinical carditis detected by echocardiography [ECHO] ), polyarthritis, chorea, erythema marginatum and subcutaneous nodules and minor criteria include arthralgia (i.e., when arthritis is not present), fever, elevated acute phase reactants (ESR>50mm/hr and CRP>30mg/L), and an electrocardiogram showing a prolonged PR interval (age adjusted and in the absence of ECHO or clinical carditis). There needs to be evidence of a preceding Group A Streptococcal infection (GAS), by streptococcal serology plus major and/or minor manifestations to indicate definite, probable, possible or recurrent ARF. The presence of two Major manifestations or of one Major and two Minor manifestations is indicative of a high probability of ARF. In high risk settings, the "Jones criteria" have been revised to include a new murmur or subclinical ECHO evidence of rheumatic carditis and aseptic monoarthritis a Major criteria.
ARF typically begins after about 3-4 weeks following a streptococcal sore throat and arthritis is often an early manifestation of the disease. Arthritis in rheumatic fever is seen in about 30-50% children and more often in children with older age at presentation. Rheumatic arthritis is an asymmetric, migratory / fleeting polyarthritis with predominant involvement of large joints of lower limbs and migrates to the upper limb. It can present with a monoarthritis. Classically, the joints are red, tender, swollen and the child cannot tolerate any movement about the joint. If untreated, then symptoms subside in about a week without residual damage followed by affection of other joint. The child responds dramatically to NSAIDS such as naproxen, ibuprofen or aspirin. Corticosteroids may be needed according to clinical scenario and presence of active carditis. The child should receive a full 10 day course of penicillin followed by prophylaxis, ongoing until they are aged 21 years or 10 years after the first episode, whichever is longer.
Further information on the diagnosis and management of ARF are available.
Revision of the Jones Criteria for the Diagnosis of Acute Rheumatic Fever in the Era of Doppler Echocardiography. A Scientific Statement From the American Heart Association and on behalf of the American Heart Association Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease of the Council on Cardiovascular Disease in the Young. Michael H. Gewitz et al.