What is rheumatic fever?
Rheumatic fever is an inflammatory disease that can develop as a complication of an infection with group A Streptococcus (GAS) bacteria. A GAS infection in the throat is more commonly known as strep throat.
Strep throat differs from a throat infection caused by a virus. It is diagnosed based on a patient’s symptoms and physical exam and confirmed with a throat swab. If the throat swab shows Streptococcus bacteria, a doctor will prescribe antibiotics to fight the infection. In most children, however, a sore throat results from a viral infection and does not need antibiotics.
Rheumatic fever does not occur after a sore throat caused by a virus. It is most common in children aged five to 15 years. It is rare in children aged under three.
Symptoms of rheumatic fever can appear two to three weeks after a GAS infection if the infection is not treated properly with antibiotics.
Signs and symptoms of rheumatic fever
Rheumatic fever can affect different parts of the body, causing inflammation in the heart, joints, skin and central nervous system (brain and spinal cord). Its symptoms vary from child to child and may change over time.
Depending on the part of the body that becomes inflamed, your child may experience:
- fever
- inflamed joints, usually in the large joints such as the knees, wrists, ankles and elbows
- shortness of breath, chest pain and difficulty breathing when lying down
- heart palpitations (a feeling of rapid, pounding or skipped heartbeats)
- skin rashes, which can appear as:
- multiple pink or light red circular spots with normal skin in the centre on the trunk (midsection) or the arms and legs
- small painless bumps under the skin, usually over bony areas or tendons
- jerky and uncontrollable movements of the face, arms and legs (known as Sydenham’s chorea)
- emotional disturbances, such as crying, restlessness or inappropriate laughing
What causes rheumatic fever?
The exact cause of rheumatic fever is not completely understood. One possible cause is that proteins in the Streptococcus bacteria look like proteins in the body's normal cells. This confuses the immune system, causing it to attack the body’s own cells by mistake. This leads to the unnecessary inflammation in healthy tissue.
How is rheumatic fever diagnosed?
If you suspect your child has strep throat, your child's doctor can diagnose it with a throat swab and prescribe antibiotics to prevent it from developing into rheumatic fever.
Your doctor will diagnose rheumatic fever by:
- examining your child for any symptoms
- using a throat swab or blood test to check for signs of a recent Streptococcus infection
- looking for signs of inflammation in the joints, skin, heart and central nervous system
To look for inflammation in the heart, the doctor might order an
echocardiogram (an ultrasound of the heart),
chest X-ray and
electrocardiogram (ECG). The echocardiogram gives information about how the valves in the heart and the muscle of the heart are working. Heart valves are often affected by rheumatic fever.
How is rheumatic fever treated?
Medications are the most common treatment for rheumatic fever.
Antibiotics
Your child’s doctor will prescribe antibiotics to treat the original GAS infection, even if your child does not have a sore throat when they meet the doctor.
Your child will normally take antibiotics orally (by mouth) for 10 days. It is very important that your child take the full 10 days of antibiotics even if they start to feel better after the first couple of days. If your child does not finish the medication, they are still at risk for rheumatic fever.
After the infection is treated, your child’s doctor may prescribe long-term antibiotics to prevent strep throat from returning until your child reaches young adulthood.
Anti-inflammatory medication
Your doctor may prescribe acetylsalicylic acid (ASA) or another anti-inflammatory medication to ease any joint pain, swelling and fever.
How to care for a child with rheumatic fever at home
- Complete the full course of antibiotics as prescribed your doctor.
- If your doctor prescribes anti-inflammatory medications, have your child take them as prescribed. Speak to your doctor or pharmacist about side effects or interactions with other medications your child takes.
- Treat fever with acetaminophen as needed.
- For painful or swollen joints, allow your child to rest as needed.
- Discuss a follow-up and long-term care plan (including antibiotics for preventing strep throat infections in the future) with your child’s doctor.
- Because rheumatic fever can cause long-term problems with the heart valves, share the diagnosis with any doctors providing health care to your child in the future.
When to see a doctor for rheumatic fever
See your child's doctor if your child has:
- a sore throat
- any of the symptoms of rheumatic fever listed above.
Call 911 or go to the nearest emergency department if your child:
- is having difficulty breathing or breathing very fast
- complains of chest pain or palpitations.
Your child may show physical changes when their condition is serious or when their condition gets worse. Parents and caregivers can learn how to spot these signs in order to seek help from a health-care provider.