What are autoinflammatory diseases?
Updated September 29, 2026
The name is a mouthful. And if you’ve been told that you or your child might have an autoinflammatory disease, the name probably raises more questions than it answers.
Is this an infection? Is it the same as an autoimmune disease? Why does the fever keep coming back?
To understand these diseases, it helps to start with something your immune system normally does very well: produce inflammation.
When the immune system sounds the alarm
Inflammation is part of your body’s defense system. When you get an infection or injure yourself, immune cells send signals that call other cells into action. The resulting inflammation helps protect you and repair the damage.
But this response needs controls. It needs to turn on when there is a problem and settle down when the job is done.
In autoinflammatory diseases, those controls do not work properly. Think of a smoke alarm that sounds even when there is no fire. The alarm is real—and so are the symptoms—but an infection may not be what set it off.
Depending on the condition, that inflammation can cause fevers, rashes, joint pain, abdominal pain, or fatigue. Some people have episodes separated by periods of feeling well. Others have symptoms or inflammation that persist between episodes. More about autoinflammatory diseases
Isn’t that what “autoimmune” means?
The words sound almost interchangeable. They describe related problems, but the distinction helps us understand what is going wrong.
Your innate immune system provides a rapid response to danger. Your adaptive immune system, which includes B cells and T cells, develops responses to specific targets and remembers what it has encountered.
Autoinflammatory diseases primarily involve problems in the innate immune system. Autoimmune diseases primarily involve the adaptive immune system mistakenly targeting the body’s own tissues.
That is a useful starting point, although the immune system is more complicated than two separate departments. The two systems communicate, and some diseases have features of both. An overview of the biology
I explain the distinction further in Autoinflammatory vs. Autoimmune: What’s the Difference?
Who gets these diseases?
Children and adults can develop autoinflammatory diseases.
Some conditions result from a change in a single gene. That change may run in a family, but it can also occur in someone whose relatives have never had similar symptoms. Other conditions do not have a single identified genetic cause. Having no family history does not automatically rule them out. NIH background, EULAR/ACR guidance
You may encounter names such as familial Mediterranean fever (FMF), TRAPS, mevalonate kinase deficiency (MKD), or cryopyrin-associated periodic syndromes (CAPS). There are plenty of acronyms to learn, but you do not need to memorize them to understand the basics.
Another example is PFAPA, which causes recurring fever, often with mouth sores, sore throat, and swollen glands in the neck. PFAPA commonly begins in childhood and often improves with age. The course of one autoinflammatory disease does not predict the course of another. Learn about PFAPA
How do we figure out what is going on?
A fever by itself does not tell us its cause. Neither does a rash or an abnormal blood test.
The pattern matters. When did the symptoms begin? How long does each episode last? Do the same symptoms return together? What happens between episodes?
Doctors combine that history with an examination and appropriate tests. Blood tests can help identify inflammation, but an elevated inflammation marker does not tell us which disease is responsible. Infections and other possible explanations also need consideration. How these conditions are evaluated
Genetic testing can be useful when a particular condition is suspected. But it is one part of the evaluation. A negative result does not exclude every autoinflammatory disease, and some genetic changes require additional testing to detect. EULAR/ACR diagnostic guidance
What can you bring to an appointment?
Remembering exactly what happened during a fever three months ago is difficult. A short diary can make the conversation much more useful.
For a printable option, see Fever and Symptom Diary: Using the AIDAI, with instructions for reviewing the diary with your clinician.
Try recording:
- When an episode starts and stops, including measured temperatures.
- Which symptoms happen together.
- How you feel between episodes.
- Medicines taken and whether they helped.
- Missed school, work, sleep, or usual activities.
Photos of a rash or swollen joint can also help explain something that has disappeared by appointment day. Bring previous test results and any family history of similar symptoms.
Your notes do not need to be elaborate. A calendar or a few lines on your phone can be a starting point. I discuss the importance of these patterns in Your Child With Frequent Fevers: Is It Autoinflammatory?
Where can you learn more?
The Autoinflammatory Alliance offers information and support for patients and families. You can also explore this site’s Resources page or, if you want to dig into the medical literature, the clinical reading list.
You do not need to arrive at your appointment knowing the diagnosis. A clear description of what has been happening is a valuable place to start.
This information is for education and does not replace medical advice from your healthcare team.
Read next
New patient guides and practical tools
FMF · CAPS · MKD/HIDS · Adult-onset disease, Still’s and VEXAS
Prepare for your visit · Understand monitoring · Daily life, school, work and transition