Your appendix is a finger-shaped pouch that’s connected to your large intestine. It can become inflamed and infected, resulting in a painful condition known as appendicitis.
Chronic appendicitis is an inflammation of the appendix that lasts for weeks, months, or even years. Appendicitis symptoms that arise — particularly pain in the lower right abdomen, where the appendix is located — can subside on their own only to return at a later time. Chronic appendicitis is estimated to account for just 1.5 percent of all appendicitis cases. (1)
Acute Appendicitis vs. Chronic Appendicitis
When people talk about appendicitis, they’re usually referring to acute appendicitis, which generally begins with abdominal pain around the belly button that then migrates to the lower right abdomen and intensifies.
Numerous other symptoms can follow, including:
- Low-grade fever
- Loss of appetite
- Inability to pass gas or stool
Acute appendicitis is typically caused by an abdominal infection that has spread to the appendix, or an obstruction — such as hardened stool, a foreign object, or an ulcer — that has blocked up the appendiceal lumen (the inner cavity of the appendix). (2)
If the appendix is not removed promptly, pressure within the organ will increase until the appendix ruptures, releasing its contents into the abdomen and potentially causing other serious infections.
Sometimes, however, the appendiceal lumen will be only partially obstructed, resulting in chronic appendicitis. Sources of the partial blockage include:
- Calcified fecal deposits called fecaliths
- Enlarged lymph tissue on the wall of the appendix
- Foreign objects such as pins, stones, and bullets
Over time, the inflammation of the appendix will worsen, and its internal pressure will build. But instead of bursting the appendix, the pressure will overcome the partial obstruction, allowing the contents of the appendix to move out of the pouch.
When this happens, appendicitis symptoms will partially or fully subside — until, that is, the obstruction causes the appendix to become inflamed again.
Like acute appendicitis, chronic appendicitis most often results in pain located in the lower right side of the abdomen. The pain may be as sharp and severe as it is with acute appendicitis, but it’s often more like a dull ache. Sometimes, abdominal pain is the only symptom that people with chronic appendicitis experience.
In other cases, people may suffer from some of the other typical symptoms of acute appendicitis, including nausea, fever, and diarrhea.
Some clinicians make a distinction between recurrent appendicitis and chronic appendicitis. A case report from 2015 described the difference between recurrent and chronic appendicitis. (3) One or more episodes of acute appendicitis, lasting one to two days, is considered recurrent appendicitis. Chronic appendicitis, on the other hand, usually occurs as a less severe, nearly continuous abdominal pain lasting longer than a 48-hour period, sometimes extending to weeks, months, or even years.
Once chronic appendicitis is properly diagnosed, removal of the appendix usually resolves the symptoms for most patients. (4)
When and Why Chronic Appendicitis Is Misdiagnosed
In the early 1900s, the diagnosis of chronic appendicitis was made relatively often. But because abdominal pain can be caused by many different diseases, including ovarian cysts, (5) indigestion, and food allergies, doctors often misdiagnosed chronic appendicitis and performed unnecessary appendectomies — the surgical procedure in which the appendix is removed.
Chronic appendicitis became controversial, with some experts questioning whether the condition existed at all. (6) Today, chronic appendicitis is well documented in the medical literature, but physicians sometimes diagnose patients with some other disease when they in fact have chronic appendicitis.
Most often, chronic appendicitis is confused with other conditions because the patient doesn’t have typical appendicitis symptoms (7) or the symptoms are thought to be the result of another condition that can cause recurrent abdominal pain or chronic inflammation, including:
- Crohn’s disease
- Ulcerative colitis
- Irritable bowel syndrome
- Pelvic inflammatory disease, which is an infection of a woman’s reproductive organs
The use of imaging techniques — including ultrasounds, magnetic resonance imaging (MRI), and, in particular, computer tomography (CT) scans — can help distinguish between these health conditions and chronic inflammation, but they’re not foolproof. For example, in at least one case, doctors used CT scans to diagnose a young woman with pelvic inflammatory disease when she actually had chronic appendicitis, according to a 2004 case report. (5) And a similar case occurred in a person with Crohn’s disease, according to a 2005 report. (8)
Regarding acute appendicitis, its symptoms are also similar to many other conditions, so it’s sometimes misdiagnosed as well, resulting in unnecessary appendectomies. A 2011 study found that almost 12 percent of all appendectomies performed in the United States between 1998 and 2007 occurred in people who did not have appendicitis, but rather some other condition. (9)
But if appendicitis is missed, it can lead to serious complications. Misdiagnosis can result in the formation of abscesses as well as infertility, according to research. (7)
Additional reporting by Deborah Shapiro.