By Dr Gavin Cleland FRACP, Regional Paediatrician, WACHS Kimberley, Adjunct Clinical Senior Lecturer, UWA
Acute Rheumatic Fever (ARF) and Rheumatic Heart Disease (RHD) continue to have a devastating impact on many young Aboriginal people in Western Australia, which can be mitigated by early diagnosis and appropriate care.
ARF is caused by an autoimmune response following infection with group A Streptococcus (‘Strep A’), a common cause of pharyngitis and of impetigo. In Australia it occurs almost exclusively among young Aboriginal and Torres Strait Islander people, particularly those aged 5-14 years, with other high-risk groups including Maori or Pacific Islander people living in households affected by crowding or lower socioeconomic status. It can present as a relatively mild illness or as fulminant carditis, and each episode may cause permanent damage to the cardiac valves, potentially requiring repair or replacement.
In the Kimberley we see ARF frequently so it’s at the forefront of our minds whenever we see a young person who has any symptoms or signs suggesting it. However, for doctors working in areas of low endemicity it is a diagnosis that can be easy to miss, potentially missing an opportunity to prevent further episodes and further cardiac damage in the future.
It’s important for all doctors who may be providing care to young people from high-risk groups to understand when to suspect ARF, and what to do when you do suspect it.
ARF classically presents with a migratory polyarthritis, but can cause arthritis in a single joint, or arthralgia alone without other signs of inflammation. It can present as carditis, typically manifested as a new cardiac murmur, or as Sydenham’s chorea, a movement disorder that can be quite subtle, and often waxes and wanes over time. These symptoms are often accompanied by fever, increased inflammatory markers (ESR and CRP), and/or a prolonged p-r interval on the ECG. ARF can also present with subcutaneous nodules or erythema marginatum, although I’ve never seen either.
Diagnosis is based on the constellation of clinical signs (using the modified Jones criteria) along with evidence of infection with Strep A from culture or serology.
Whenever we see a young person from a high-risk group who has arthritis of any joint, a new murmur, or chorea, we treat them as a likely case of ARF up until we’ve either confirmed the diagnosis or ruled it out. Assessment and initial management should always be done as an inpatient, even for a mild illness. It’s critical that we get the diagnosis right at the time of presentation, and attempts at outpatient assessment typically result in an incomplete diagnostic assessment which can not be clarified retrospectively at a later date. Investigations should include ECG, bloods (ESR, CRP, ASOT, and antiDNase B), swabs of any skin or throat infection, and an echocardiogram. Any suspected case should be discussed with a cardiologist, paediatrician or physician who is familiar with the condition. Suspected cases should all receive a dose of intramuscular benzathine benzylpenicillin G, which is continued monthly for at least 10 years to prevent recurrence.
Fortunately, some cases of ARF can be prevented through timely, appropriate antibiotic treatment for skin and throat infection. All cases of sore throat and/or impetigo (‘skin sores’) in someone from a high-risk population need to be treated with appropriate antibiotics, even if you think the illness is likely to be viral.
Summary
Young people in WA continue to be affected by ARF, but fortunately we can prevent some cases, and improve the outcome for others, through timely and appropriate action in primary care, including:
- Appropriate use of antibiotics for sore throats and impetigo in people who are at high-risk
- Recognition of the signs of possible ARF
- Specialist consultation and referral for admission for all suspected cases
Valuable resources to assist you in assessment and management of ARF include the Acute Rheumatic Fever HealthPathway, and RHD Australia resources including the Diagnosis Calculator App and the 2020 Australian guideline for prevention, diagnosis, and management of ARF and RHD