Learn about this complication of strep throat and scarlet fever and what you can do to prevent it.
Update Date: 09.06.2026
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:
Some people with rheumatic fever get a condition called Sydenham chorea. Symptoms of this condition include:
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:
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:
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:
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 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.
The goals of treatment for rheumatic fever are to:
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.
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.
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:
For rheumatic fever, basic questions to ask the care team include:
Don't hesitate to ask other questions.
The healthcare team is likely to ask questions, such as:
© 2026 Mayo Foundation for Medical Education and Research. All rights reserved. Terms of Use