Overview

Rheumatic fever is an inflammatory disease that can develop when strep throat or scarlet fever isn't properly treated. Strep throat and scarlet fever are caused by an 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 are used to treat pain and prevent complications.

Symptoms

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 several. 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 develop a condition called Sydenham chorea. Symptoms of this condition include:

  • Jerky, uncontrollable body movements, most often in the hands, feet and face.
  • Outbursts of crying or inappropriate laughing.

When to see a doctor

Properly treating strep throat 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.

Causes

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. Improperly treated strep throat or scarlet fever infections cause 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.

Risk factors

Things that may increase the risk of rheumatic fever include:

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

Complications

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.

However, 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 possibly connect together. This decreases 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 irregular and very fast heartbeats. This also is known as atrial fibrillation (AFib).

Prevention

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.

By Mayo Clinic Staff