What is pericarditis?

The pericardium is a thin membrane that surrounds the heart like a sac. It provides lubrication for the heart, contains it within the chest cavity, and shields it from infection and other types of harm.


Pericarditis is a condition in which that membrane becomes inflamed (in medicine “itis” means “inflamed”). When this happens, the irritated layers of the pericardium rub against each other and can cause a lot of pain.


An episode of pericarditis is often called a Flare.


Different types of pericarditis

Two types of pericarditis may include a first or one-time episode or recurrent pericarditis.

One-Time Pericarditis Heart Graphic

first or One-time episode pericarditis

The first episode of pericarditis is often a single flare that goes away completely on its own or after treatment.

Average duration: 4 to 6 weeks.

Recurrent Pericarditis Heart Graphic

Recurrent pericarditis

Just like it sounds, recurrent pericarditis is when a pericarditis flare happens again more than 4 weeks after the first one. Flares of recurrent pericarditis can happen repeatedly.

Average disease duration: about 3 years for people who have 2 or more recurrences.


1 in 3 people infographic

Up to 1 in 3 people

with a first episode of pericarditis will experience recurrent pericarditis within 18 months of their first flare.



people in the United States seek care for recurrent pericarditis annually.1


In a study of 7502 patients with pericarditis:



of people with 1 flare had a second flare
(2096 of 7502 patients)



of people with 2 flares had a third flare
(994 of 2096 patients)



of people with 3 flares had a fourth flare
(541 of 994 patients)

With each recurrent pericarditis flare, the time in between flares decreases.

Recurrent pericarditis is unpredictable and can last for many years

In a study of people with recurrent pericarditis, researchers found that the disease could last (on average) about:


for people who experienced just 1 recurrence


for people who experienced 2 or more recurrences

In this study of 944 people with recurrent pericarditis (observed over 10 years), 569 had 1 recurrence and 375 had 2 or more recurrences.


Possible causes of a first OR ONE-TIME episode

Even though a first or one-time episode and recurrent pericarditis share the same symptoms, they have different causes. For this reason, treatments that relieve symptoms in people with a first episode may not be able to prevent future flares in people with recurrent pericarditis.

There are a number of possible causes for a first or one-time episode:

Heart attack icon

Heart attack and heart procedures

Infection icon

Infection from a virus, bacteria, fungus, or parasite

Medications icon

Certain medications, such as blood thinners or those for seizures or irregular heart beat

Pericardium injury icon

Injury to the pericardium, such as from an accident, radiation, or chemotherapy

Other illnesses icon

Other illnesses, especially autoimmune disorders such as lupus or rheumatoid arthritis

Idiopathic icon

Unidentified: most first or one-time episodes of pericarditis are idiopathic, which means “unknown”*

*Likely caused by an undiagnosed virus or the body’s immune response to a past viral illness.


Recurrent pericarditis is an autoinflammatory disease, which means flares are caused by the body’s immune system attacking the pericardium.


”Self” or automatic


The painful swelling that happens as the body’s natural response to injury or infection

Each immune system attack causes inflammation that leads to more immune system response in an ongoing cycle.


Recurrent pericarditis occurs when proteins called IL-1α and IL-1β signal the immune system to attack the pericardium. Each attack causes inflammation that leads to more attacks in an ongoing cycle of autoinflammation.

The Cycle of Autoinflammation in Recurrent Pericarditis

IL-1, interleukin-1.

Traditional therapies—such as nonsteroidal anti-inflammatory drugs (NSAIDs), colchicine, and corticosteroids—are often used to manage symptoms of a first episode of pericarditis. Treatment for recurrent pericarditis needs a different approach because traditional therapies do not specifically target the ongoing cycle of autoinflammation that causes recurrent pericarditis.

Long-term prevention of flares requires a treatment that can break the cycle of autoinflammation.


With a “rare disease” like recurrent pericarditis, it is especially important that you communicate with your doctor how the disease is affecting your life and what you need from treatment and from your care team.

These results from a poll of people with recurrent pericarditis showed that while the disease had a significant impact on their lives, both physically and emotionally, there is a need for better communication between doctors and their patients with recurrent pericarditis.

Impact of recurrent pericarditis


feel that recurrent pericarditis disrupts their life in the time between flares.


experience negative physical, mental, or emotional impact from flares even after a flare has resolved.


worry they could have a flare at any time.


have withdrawn from many aspects of life due to fear or anxiety about having a flare.


missed important events or functions because of their recurrent pericarditis.

Quality of communication

Respondents said they had to go to an average of 3 doctors before being diagnosed.


want their doctor to ask more questions about recurrent pericarditis and/or flares.


often feel they “fall through the cracks.”


would like a treatment that prevents future flares better than their current treatment.

This survey was conducted online within the United States by The Harris Poll on behalf of Kiniksa Pharmaceuticals from May 4 to June 1, 2023, among 125 US adults ages 18+ who have been diagnosed with recurrent pericarditis and are not currently pregnant or breastfeeding and have never used/are not currently using an IL-1 antagonist. The sampling precision of Harris online polls is measured by using a Bayesian credible interval. For this study, the sample data are accurate to within +/- 8.7 percentage points using a 95% confidence level.

Yvette thumbnail

Tips from Yvette

A working mother of 2 active teenagers. Diagnosed with recurrent pericarditis in 2021.

Yvette suffered for over a year. Her journey included misdiagnosis, emergency room visits, inadequate treatment, and surgery on her heart. Based on her experience, here are a few tips for other people with recurrent pericarditis:

Advocate for yourself

Recurrent pericarditis is a rare disease. Many doctors may not recognize it or know how to treat it, so learn all you can, and when you talk to your doctor, don’t just listen. Make it an active conversation:

  • Come with notes regarding your symptoms
  • Research possible treatments and discuss them during your visit
  • Write down any questions you may have, and write down or record your doctor’s answers
  • Communicate your goals for treatment

Take care of your mental health

A therapist cannot diagnose or treat recurrent pericarditis, but if your disease is making you anxious or depressed, a mental health professional may be able to help.

Participate in a support group

Friends and family may be helpful and supportive, but it can also be invaluable to have people in your life who have shared similar experiences with recurrent pericarditis.


Have you asked your doctor about ARCALYST? Download a discussion guide for your next doctor’s visit.

Treating recurrent pericarditis

After you have been diagnosed, your doctor will prescribe a treatment or treatments to help manage your recurrent pericarditis.

medications used to help manage symptoms

Traditional therapies—such as NSAIDs, colchicine, and corticosteroids—are often used to manage symptoms of a first or one-time episode of pericarditis.

  • Doctors often try to limit the use of corticosteroids due to side effects and that steroids may contribute to recurrent pericarditis lasting longer

Treatment for recurrent pericarditis needs a different approach because these traditional therapies: 

  • Do not specifically target the ongoing cycle of autoinflammation that causes recurrent pericarditis

Not FDA approved to treat recurrent pericarditis.

Arcalyst injection bottle

Medication used to treat recurrent pericarditis

  • ARCALYST is the first and only FDA-approved therapy to treat recurrent pericarditis and reduce the risk of future flares in people 12 years and older
  • ARCALYST breaks the cycle of autoinflammation that causes recurrent pericarditis by blocking interleukin-1 (IL-1) signaling

If you experience another flare more than 4 weeks after one ends, ask your healthcare provider about ARCALYST.