Acute rheumatic fever is an autoimmune multisystem inflammatory disease caused by a type of bacteria known as the Group A BETA HEMOLYTIC streptococcus (GAS). It is commonly known as strep bacteria. It usually occurs when a throat (strep throat) or skin infection (scarlet fever) caused by the strep bacteria is not treated properly with antibiotics.

Acute rheumatic fever generally affects children between 5 to 15 years of age, especially in developing countries.

Acute rheumatic fever can affect the heart, joints, brain and skin. Its effect on the heart is of particular concern, as it can lead to permanent valve damage and heart failure.

What causes acute rheumatic fever?

Acute rheumatic fever is an autoimmune disease, a condition where the body attacks its own cells, mistaking it as a foreign particle.

The bacterial cell wall protein share identity with certain tissues in our body (e.g. heart valve). The body’s immune system attacks its own tissues containing this protein, thinking it to be a bacterial protein. This triggers a reaction and results in inflammation of the tissues of the heart, joints, skin and the nervous system.

The chances of developing rheumatic fever remain high in those with a history of 1 or more episodes of Strep throat or scarlet fever which has not been treated appropriately. It usually develops 14-28 days after a Strep infection.

It is rare in children who receive appropriate antibiotic treatment for Strep bacteria.

Is it contagious?

No, rheumatic fever is not contagious.

It is due to an individual’s immune response and is not an infection. However, people with strep throat or scarlet fever can spread the bacteria to others through respiratory droplets.

Who is at risk of having a rheumatic fever?

Some people are at higher risk of suffering from acute rheumatic fever as compared to others due to the following factors of

Family history: Some people carry genes that make them more susceptible to develop autoimmune diseases such as rheumatic fever
Type of strep bacteria: an infection caused by certain strains of the GAS bacteria are more likely to cause rheumatic fever
Environmental/hygiene factors: Unhygienic conditions such as overcrowding and poor sanitation can result in rapid transmission and multiple exposures to GAS. This can result in rheumatic fever. The strep bacteria spread easily through AIR DROPLETS from one person to another, especially by breathing or coughing.

What consists of acute rheumatic fever symptoms?

The classical acute rheumatic fever symptoms include fever and pain in the joints. However, symptoms may vary from one person to another and also change during the course of the disease.

Symptoms occur as a result of inflammation in the heart, joints, skin and central nervous system and can include

Fever
Fatigue
ARTHRITIS or inflammation in joints. Arthritis occurs in about 70% of patients, presents as painful, red hot and swollen joints mainly affecting predominantly large joints like knees, ankles, elbows and wrists. Arthritis is characteristically migratory and additive. It initially involves one joint and then the other joint is involved. The symptoms in the affected joint usually resolves spontaneously within few hours of onset only to re-appear in a different joint.
Small, painless bumps over the elbows, wrists, knees, ankles and areas near the spine known as subcutaneous nodules
Skin rash mainly found on the trunk of the body called as erythema marginatum
Chest pain, breathlessness and a heart murmur on auscultation
Jerky, uncontrollable body movements of the hands, feet and face known as Sydenham chorea
Emotional outbursts such as crying or inappropriate laughing

rheumatic fever affects

How is it diagnosed?

There is no single and specific test available currently to confirm rheumatic fever diagnosis. The doctor will need a complete medical history, conduct a physical examination and order some laboratory tests to confirm the disease. Tests may include

Throat culture testor Rapid antigen test to confirm GAS infection
C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) tests are done to check for the presence of inflammatory markers in the body
Electrocardiogram (ECG): This test can detect abnormal electrical activity of the heart
Echocardiogram: This test creates a live-action image of the heart to detect abnormal heart functioning

What are the diagnostic criteria for rheumatic fever?

Diagnostic criteria for rheumatic fever are set of clinical features and laboratory findings in a patient which help the doctor to confirm the diagnosis.

The first rheumatic fever diagnostic criteria were developed by a scientist named Jones in 1944. It was later modified by the American Heart Association in 1992. The latest rheumatic fever Jones criteria have been published in 2015.

You can have an idea of the Jones criteria by looking at the below table. However, its exact interpretation can be done only by a clinician. The major criteria include the main clinical presentation whereas the minor criteria comprise of other clinical presentation and laboratory tests.

2015 Revised Jones criteria rheumatic fever

Major criteria
Low risk population	High risk population
Carditis (clinical or subclinical)	Carditis (clinical or subclinical)
Arthritis- only polyarthritis	Arthritis- monoarthritis or polyarthritis
Chorea	Chorea
Erythema marginatum	Erythema marginatum
Subcutaneous nodules	Subcutaneous nodules

Minor criteria
Low risk population	High risk population
Polyarthralgia	Monoarthralgia
Hyperpyrexia (≥38.5°C)	Hyperpyrexia (≥38°C)
ESR ≥ 60mm/h and/or CRP ≥ 3.0 mg/dl	ESR ≥ 30mm/h and/or CRP ≥ 3.0 mg/dl
Prolonged PR interval (after taking into account the differences related to age; if there is no carditis as a major criterion)	Prolonged PR interval (after taking into account the differences related to age; if there is no carditis as a major criterion)

What is the most common complication of acute rheumatic fever?

The most common complication of rheumatic fever includes rheumatic heart disease. It is a condition that can result in permanent heart damage.

Acute rheumatic fever does not cause any long-lasting damage to the brain, joints or skin, except for the heart.

Recurrent strep infections and acute rheumatic fever can further worsen rheumatic heart disease. Though heart complications usually occur after 10-20 years after Strep infection, it may occur within days in case of serious infection.

Heart complications can arise due to the following conditions

Narrowing of the heart valves resulting in reduced blood flow
Leaky valves cause the blood to flow in the wrong direction
Inflammation of the heart weakens the heart muscles, thereby affecting its ability to pump

The above changes can increase the risk of heart conditions such as

Atrial fibrillation – a condition marked by irregular and chaotic heartbeat
Heart failure – a condition where the heart is unable to pump blood effectively

How long does acute rheumatic fever last?

An acute episode can last from about 6 weeks to more than 6 months.

How is acute rheumatic fever treated?

The goals of acute rheumatic fever treatment include eliminating GAS bacteria, relieve symptoms of fever and pain, control inflammation and prevent future risk of re-infection.

Treatment primarily consists of:

Antibiotics are used to treat strep infection completely. The length of antibiotic therapy can last for 5-10 years or longer depending upon the patient’s conditions. It is important to complete the entire course of antibiotics therapy to avoid re-infections and risk of rheumatic heart fever.
Pain killers andantipyretics are prescribed to control fever, joint pains and reduce inflammation. However, these drugs are associated with several side-effects and should not be used for a long period of time unless recommended by the doctor.
Corticosteroids are generally reserved for patients with severe cardiac involvement.
Anti-convulsantor antiseizure medications are generally used to treat involuntary movements caused by Sydenham chorea.

Is acute rheumatic fever preventable?

The only way to prevent acute rheumatic fever is to treat Strep throat or scarlet fever appropriately and promptly with prescribed antibiotics.

It is advisable to seek medical help in case of the following symptoms of:

Sore throat and fever lasting for >24 hours
Severe sore throat without cold symptoms
Sore throat after being around someone with a strep throat

What are the symptoms of rheumatic heart disease?

There may be no symptoms for many years. Symptoms usually depend on the heart valve affected and the severity of the damage. Patients may suffer from the following symptoms of

Chest pain
palpitations
Breathlessness while lying down
Weakness and tiredness
Swelling of the legs and face

rheumatic heart disease symptoms

How is rheumatic heart disease diagnosed and treated?

The above symptoms along with some tests can help the doctor to establish the diagnosis

Tests generally include

Echocardiogram (echo)
Electrocardiogram (ECG)
Chest X-ray
Blood tests

Mild valve leakage may not require any treatment. However, surgery may be needed if the valve leakage is severe enough to affect heart functioning.

Surgery can involve either repair of the damaged valve or replacement with an artificial valve, depending upon the severity of the damage.

Conclusion:

Acute rheumatic fever is an autoimmune disease, a condition marked by fever and severe pain and inflammation of the joints. It is caused by Group A streptococcus (GAS), commonly known as the strep bacteria. It usually occurs when a throat (strep throat) or skin infection (scarlet fever) caused by the strep bacteria is not treated timely and appropriately with antibiotics.

Acute rheumatic fever generally affects children between 5 to 15 years of age, especially in developing countries. An acute episode can last from about 6 weeks to more than 6 months.

The most serious complication of acute rheumatic fever is rheumatic heart disease. This heart condition is characterised by damaged valves and increased risk of heart failure and atrial fibrillation.

Clinical examination by doctor and blood tests along with ECG, 2D Echo and Chest X-ray are the cornerstone of diagnosis. The Jones Criteria is widely used by medical practitioners to establish the diagnosis in suspected patients.

The only way to prevent acute rheumatic fever is to treat Strep throat or scarlet fever appropriately and promptly with prescribed antibiotics.

Reference:

Rheumatic fever. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/rheumatic-fever/symptoms-causes/syc-20354588.
What is acute rheumatic fever? RHD Australia. https://www.rhdaustralia.org.au/what-acute-rheumatic-fever
Rheumatic fever: All you need to know. CDC. https://www.cdc.gov/groupastrep/diseases-public/rheumatic-fever.html.
Szczygielska I, et al. Rheumatic fever – new diagnostic criteria. Reumatologia. 2018; 56(1):37-41. DOI: https://doi.org/10.5114/reum.2018.74748.
Rheumatic fever. Summit Medical Group. https://www.summitmedicalgroup.com/library/adult_health/aha_rheumatic_fever/.
Kumar RK, Tandon R. Rheumatic fever & rheumatic heart disease: the last 50 years. Indian J Med Res. 2013;137(4):643-58. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3724245/.