Rheumatic fever is a disease that causes swelling called inflammation in joints and some organs. The condition can happen when strep throat or scarlet fever isn't properly treated. Strep throat and scarlet fever are caused by a bacterial infection with streptococcus (strep-toe-KOK-us) bacteria.

Rheumatic fever most often affects children ages 5 to 15. But younger children and adults can get it too. Rheumatic fever is rare in the United States and other developed countries.

Rheumatic fever can cause long-lasting heart damage, including heart valve problems and heart failure. Treatment includes medicines to kill the strep bacteria. Other medicines can treat pain and prevent complications.

Rheumatic fever symptoms usually start about 2 to 4 weeks after a strep throat infection. Symptoms are due to swelling, called inflammation, in the heart, joints, skin or central nervous system. There may be few symptoms or many. Symptoms can come and go or change while a person is sick with rheumatic fever.

Rheumatic fever symptoms can include:

• Fever.
• Joint pain or swelling — most often the knees, ankles, elbows and wrists. Joints may feel hot or tender.
• Pain in one joint that travels to another joint.
• Chest pain.
• Fatigue.
• Small, painless bumps beneath the skin.
• Flat or slightly raised, painless rash with a ragged edge.

Some people with rheumatic fever get a condition called Sydenham chorea. Symptoms of this condition include:

• Jerky body movements that a person can't control, most often in the hands, feet and face.
• Outbursts of crying or laughing for no clear reason.

When to see a doctor

Proper treatment of strep throat or scarlet fever can prevent rheumatic fever. Make an appointment with a healthcare professional if any of these symptoms of strep throat occur:

• Sore throat that comes on suddenly.
• Pain when swallowing.
• Fever.
• Headache.
• Stomach pain, nausea and vomiting.

Rheumatic fever can happen after a throat infection from group A streptococcus bacteria, also called strep bacteria. The bacteria cause strep throat and scarlet fever. Improper treatment of strep throat or scarlet fever infections causes rheumatic fever.

There's little chance of getting rheumatic fever when strep throat is treated right away with antibiotics. It's important to finish all of the medicine.

Group A strep infections of the skin or other parts of the body rarely cause rheumatic fever.

How a strep infection causes rheumatic fever isn't clear. It may be that the bacteria trick the body's immune system into attacking healthy tissue. This usually happens in the heart, joints, skin and central nervous system. The incorrect immune system reaction causes swelling of joints and tissues. This swelling is called inflammation.

Things that may raise the risk of rheumatic fever include:

• Genes. Some people have one or more genes that might make them more likely to get rheumatic fever.
• Specific type of strep bacteria. Some strains of strep bacteria are more likely than others to cause rheumatic fever.
• Factors in the environment. Overcrowding, poor sanitation and other conditions can cause strep bacteria to easily spread among many people. These conditions raise the risk of rheumatic fever.

Joint and tissue swelling caused by rheumatic fever can last a few weeks to several months. For some people, the swelling causes long-term complications.

One complication of rheumatic fever is long-lasting heart damage. This is called rheumatic heart disease. Rheumatic heart disease usually occurs years to decades after the original illness.

But severe rheumatic fever can start to damage the heart valves while a child still has symptoms of the infection. The valve between the two left chambers of the heart is most commonly affected. This valve is called the mitral valve. But other heart valves also may be affected.

Rheumatic fever can cause these types of heart damage:

• Narrowing of a heart valve, also called valve stenosis. The valve flaps become thick or stiff, and they may connect together. This lessens blood flow through the valve.
• Backward flow of blood across a heart valve. This is called valve regurgitation. It occurs when the valve flaps don't close properly.
• Damage to heart muscle. Tissue swelling from rheumatic fever can weaken the heart muscle. This damage may affect the heart's ability to pump.
• Heart failure. Heart damage from rheumatic fever also may cause heart failure later in life.
• Irregular heartbeats. Damage to the heart valves or other areas of the heart can lead to an irregular and very fast heartbeat called atrial fibrillation, also known as AFib.

The best way to prevent rheumatic fever is to treat strep throat infections or scarlet fever right away. It's also important to finish all of the prescribed antibiotics as directed.

There's no single test for rheumatic fever. Diagnosis of rheumatic fever is based on medical history, a physical exam and certain test results.

Tests

Tests for rheumatic fever include:

• Blood tests. Blood tests can help check for signs of inflammation in the body. These tests include C-reactive protein, also called CRP, and the erythrocyte sedimentation rate, also called ESR or the sed rate.

  Sometimes the actual strep bacteria can no longer be found in the blood or in throat tissues. Another blood test can be done to look for proteins related to the strep bacteria. These proteins are called antibodies.

• Electrocardiogram, also called ECG or EKG. This test shows how the heart is beating. It can help diagnose irregular heartbeats. A healthcare professional can check ECG signal patterns for signs of heart swelling.
• Echocardiogram. This tests uses sound waves to create pictures of the heart in motion. An echocardiogram shows the structure of the heart and how blood flows through it.

The goals of treatment for rheumatic fever are to:

• Treat the infection.
• Ease symptoms.
• Control swelling, called inflammation.
• Prevent the condition from coming back.

Medicines

Rheumatic fever is treated with medicines, including:

• Antibiotics. Penicillin or another antibiotic usually is given to kill the strep bacteria.

  After the first antibiotic treatment is fully finished, another round of antibiotics may be given. This stops the rheumatic fever from coming back. A child might need to keep taking antibiotics for five years or through age 21 to prevent rheumatic fever from coming back, whichever is longer.

  People who had heart inflammation during rheumatic fever might need to keep taking antibiotics for 10 years or longer.

• Anti-inflammatory medicines. Aspirin or naproxen (Naprosyn, Naprelan, Anaprox DS) can help lessen inflammation, fever and pain. If symptoms are very bad or don't get better with anti-inflammatory medicines, a corticosteroid might be given. Don't give a child aspirin unless a healthcare professional tells you to do so.
• Antiseizure medicines. Medicines such as valproic acid or carbamazepine (Carbatrol, Tegretol, others) may be used to treat severe movements that a person can't control caused by Sydenham chorea.

It's important to have regular health checkups after having rheumatic fever. Heart damage from rheumatic fever might not show up for many years — even decades. Always tell your healthcare professional about any history of rheumatic fever.

A healthcare professional might recommend bed rest for someone with rheumatic fever. There may be limits on activity until symptoms get better. Ask your healthcare professional if bed rest is right for you.

Make an appointment for a health checkup if symptoms of rheumatic fever start. If there is heart damage, you may be sent to a doctor called a cardiologist who is trained in heart diseases.

Here's some information to help you get ready for the appointment.

What you can do

When you make the appointment, ask if there's anything you need to do to get ready. For example, you may not be able to eat or drink for a while before some blood tests. Make a list of:

• The symptoms, including any that don't seem related to the reason for the appointment.
• Important personal information, including major stresses, recent life changes and family medical history.
• All medicines, vitamins or other supplements being taken. Include the doses.
• Questions to ask the healthcare team.

For rheumatic fever, basic questions to ask the care team include:

• What are the possible causes of the symptoms?
• What tests are needed?
• What treatment is needed?
• What are the main treatment options that you're suggesting? Are there other options?
• My child or I have other health conditions. How can we best manage them together?
• Are there activity or diet restrictions?
• Should we see a specialist?
• Are there brochures or other printed material that I can have? What websites do you recommend?

Don't hesitate to ask other questions.

What to expect from your doctor

The healthcare team is likely to ask questions, such as:

• When did the symptoms begin?
• What, if anything, seems to make the symptoms better?
• What, if anything, appears to make the symptoms worse?
• Do the symptoms happen all the time or do they come and go?
• Has anyone in your family been sick with a cold or flu lately?
• Is there a history of strep throat or scarlet fever?
• If so, were all antibiotics taken as prescribed?