Myocarditis has been a topic in the news in recent weeks, specifically myocarditis in children. Understanding the facts about what myocarditis is, symptoms and what causes this cardiac condition is important to supporting the health of your child. Myocarditis is a rare occurrence in children of inflammation of the heart muscle (myocardium), which pumps blood throughout the body.

Causes of myocarditis in children

According to the American Academy of Pediatrics, inflammation of the heart muscle can result from a number of causes. In most cases, myocarditis in children is caused by a virus, bacteria or fungus infecting the heart. The body’s defense systems send more white blood cells to the infected area, which can cause the heart to become inflamed. This inflammation can cause an abnormal heart rhythm and poor heart muscle function, which can, but does not always, result in permanent damage.

Viruses that can cause myocarditis in children include:

• Common cold
• COVID-19*
• Epstein-Barr virus
• Enterovirus
• Gastrointestinal viruses
• Herpes simplex
• HIV
• Influenza (flu)
• Parvovirus
• Rubella
• Viruses causing hepatitis B and C

*According to the American Academy of Pediatrics, myocarditis risk is 37 times higher for children with COVID-19.

One way to help protect your child from extreme cases of the above viruses is through vaccinations. Food and Drug Administration (FDA)-approved vaccinations are available for COVID-19, flu, rubella (the measles-mumps-rubella or MMR vaccine), hepatitis B and polio (an enterovirus).

Bacteria that can cause heart inflammation in children include Lyme disease or toxic shock syndrome, though the number of cases resulting from either is rare. Other conditions that may be linked to myocarditis include:

• Carbon monoxide or radiation exposure
• Fungi (children with weakened immune systems more susceptible)
• Medications like chemotherapy
• Parasites
• In exceedingly rare cases, lupus, rheumatoid arthritis, ulcerative colitis and scleroderma

Symptoms of heart inflammation in children

Myocarditis can be difficult to diagnose in children because the symptoms are similar to that of other conditions. Symptoms also vary between newborns and infants and older children.

Newborns and infants: Because a newborn’s immune system is still developing, they are more susceptible to infections and bacteria. Symptoms of myocarditis in newborns and infants include:

• Cool hands and feet, resulting from poor blood circulation
• Difficulty eating and breathing
• Fatigue/sleeping more
• Fever
• Fussiness/irritability
• Less urine output because their kidneys are not functioning properly
• Listlessness
• Pale skin

Older children: Older children generally have more severe symptoms, which include:

• Belly pain
• Cough
• Chest pains
• Fainting
• Fatigue
• Heart palpitations
• Inability to tolerate exercise
• Nausea
• Shortness of breath
• Swelling in the legs, feet or face

Treatment for myocarditis in children

Usually, myocarditis goes away on its own, with no severe, permanent damage. However, during the period when the heart is inflamed, medical intervention at a hospital intensive care unit may be needed to support heart function. If untreated, there is a higher risk of children developing long-term heart disease.

In-patient treatment may include:

• Antibiotics to fight infection
• Diuretics to help rid fluid from the body tissue
• Intravenous immunoglobulin, which helps control the inflammatory process
• Steroids to control inflammation
• Medication to treat symptoms of heart failure or abnormal heart rhythms
• Severe cases: mechanical support pump to aid the heart’s ability to pump

With appropriate medical treatment, most children with myocarditis either have complete recovery or improvement in heart function within two to three months of the onset of symptoms. Ongoing follow-up care with a pediatric cardiologist is also needed.