What is Pseudoappendicitis?
Pseudoappendicitis is a term used for any condition that resembles acute appendicitis, a sudden inflammation of the appendix. The usual signs of this condition include severe pain in the lower right side of your stomach, loss of appetite, and a specific kind of tenderness in the same area of your stomach.
More often than not, this condition is caused by a disease called acute yersiniosis, a disease transmitted from animals to humans and caused by a bacteria known as Yersinia enterocolitica. However, in some rare instances, pseudoappendicitis can be a result of a Campylobacter infection, another type of bacteria. These bacteria can both lead to symptoms similar to appendicitis such as pain in the lower right side of your stomach, fever, vomiting, rising white blood cells, and light diarrhea. In more severe cases, it can cause inflammation of the lymph nodes in the stomach or the lower part of the small intestine, but most often, it is mild and gets better on its own.
People with weaker immune systems are more likely to get infected by Yersinia enterocolitica and are also at a higher risk of developing serious issues, including sepsis (a life-threatening infection) and abscesses (a pocket of pus) in the spleen or liver. People with a genetic condition called hereditary hemochromatosis (a condition that leads to too much iron in the body) are also more likely to get this infection- the higher levels of iron in their body create a favorable environment for this bacteria.
This bacteria, Yersinia enterocolitica, is also the most common bacteria found in stored blood used for transfusions. While most people with acute yersiniosis will experience mild symptoms that go away on their own, older people and those with other health conditions have an increased risk of infection and serious symptoms. If you have received a blood transfusion recently and develop unusual symptoms such as fatigue, stomach issues, and abdominal pain, you should get checked for a Yersinia enterocolitica infection.
What Causes Pseudoappendicitis?
The syndrome of pseudoappendicitis, which may show similar symptoms to appendicitis, is most often caused by conditions known as acute yersiniosis or Campylobacter infection.
Risk Factors and Frequency for Pseudoappendicitis
Acute yersiniosis can often appear similar to acute appendicitis. There was a particular instance where an unusually high number of people displayed symptoms much like appendicitis during an outbreak of acute yersiniosis. Roughly 42% of these people went through an appendectomy – a surgical procedure to remove the appendix. In other yersiniosis outbreaks, the appendectomy rates have ranged from 0% to 14%. This shows the key role of acute yersiniosis posing as a false case of appendicitis.
In regions where yersiniosis is common, the infection leads to many appendectomies. One research study in Belgium tested 2,861 patients undergoing appendectomies for what was thought to be acute appendicitis. They found that 3.6% of these patients actually had harmful yersinia enterocolitica – the bacterium causing yersiniosis. More surprisingly, 75% of these patients had inflammation in the lymph nodes of the intestine or the end of the small intestine, rather than acute appendicitis, during their surgical examination.
Signs and Symptoms of Pseudoappendicitis
The pseudoappendicitis syndrome can present with a variety of signs and symptoms, and may depend on its underlying cause. However, there are a few symptoms that are generally quite common.
People who have had an appendix removal but continue to experience unresolved or worsening abdominal pain could potentially suffer from pseudoappendicitis. This is especially likely if lab tests and imaging studies do not show any specific cause. Doctors sometimes erroneously label this continuous abdominal pain as a psychological health issue.
A type of bacterial infection, Y enterocolitica, is often without symptoms. Nevertheless, some people may experience mild abdominal pain and diarrhea. If the disease becomes severe, the individual may have fever, chills, excessive abdominal pain and diarrhea which could be either watery or bloody. When this infection affects the lymph nodes in the abdomen, it can cause severe pain in the lower right side of the abdomen mimicking symptoms of acute appendicitis. These symptoms can be further detailed as:
- Abdominal pain that intensifies
- Protecting or “guarding” of the stomach
- Increased pain when pressure is released, known as rebound tenderness
- Positive McBurney sign, indicating inflammation near the end of the small intestine
Sometimes, patients with severe diarrhea due to this bacterial infection could be wrongly diagnosed as having other conditions like salmonella, shigella or Giardia infections.
Advanced infections can get serious if not treated. Some people may show signs of severe infection (sepsis), dehydration, and shock.
Testing for Pseudoappendicitis
A stool culture is a test that can identify certain bacteria known to cause symptoms that mimic appendicitis – like Campylobacter, Salmonella, Shigella, and Yersinia. However, this test has its limitations. Results can take a few days, which can delay both the confirmation of diagnosis and the start of the needed treatment. Moreover, only bacterial causes of these symptoms can be identified through this method, so if your symptoms are caused by non-bacterial factors, the test will not be useful. Nevertheless, if you have stomach-related symptoms and Yersinia is suspected, the stool culture is the recommended test.
There’s also a method called Nucleic acid amplification testing (NAAT), which includes something known as reverse transcription polymerase chain reaction (RT-PCR). This is a sophisticated test that can find and magnify the specific genetic material of certain disease-causing organisms. Because it’s so sensitive, it can detect even small amounts of these organisms. As it can quickly and accurately identify bacteria like Campylobacter, it’s been instrumental in diagnosing various infectious diseases. However, as with the stool culture, this test can only identify specific organisms, so if your symptoms are due to other causes, it may not be effective. Additionally, this method might not be routinely available in all healthcare settings due to cost considerations.
Fecal microscopy is another method where a stool sample is examined under a microscope to find particular microorganisms or white blood cells. While this can provide useful information, it is not the main method to diagnose symptoms that mimic appendicitis. It’s typically used to identify specific infections, and while it can sometimes support a diagnosis of a Campylobacter infection, its effectiveness in diagnosing symptoms mimicking appendicitis is limited.
A test for a substance called calprotectin might also be useful. This substance is released into the intestines during the early stages of intestinal damage, and it resists breaking down at room temperature, making it a stable marker for disease. It’s an attractive option because the sample collection is noninvasive, and this test has proven valuable for diagnosing various bowel conditions, including chronic inflammatory bowel diseases.
Imaging methods, like computed tomography (CT), can sometimes spot conditions that cause similar symptoms to appendicitis. These conditions tend to develop gradually, in contrast to the faster progression of inflammation seen in cases of actual appendicitis. However, differentiating between these conditions and real appendicitis based on CT images can be challenging.
Treatment Options for Pseudoappendicitis
Most infections caused by the Y enterocolitica bacteria tend to go away on their own and don’t need treatment. However, if a person experiences severe symptoms such as diarrhea and dehydration, they will need treatment to replenish their body’s fluid levels and stabilize their condition. This is typically done using intravenous fluids, which are fluids given directly into a vein.
Antibiotics, which are drugs used to treat bacterial infections, are usually not needed in these cases. However, they may be used in severe cases where symptoms do not improve with the initial treatment. They may also be necessary for patients with weakened immune systems.
Most types of Y enterocolitica bacteria can break down certain antibiotics like penicillins and cephalosporins, rendering them ineffective. As a result, a combination of other antibiotics such as doxycycline and an aminoglycoside, is often used. Other antibiotics that could be used include trimethoprim-sulfamethoxazole, fluoroquinolones, chloramphenicol, and third-generation cephalosporins.
Patients with weakened immune systems who develop abscesses, or pockets of pus, in the spleen or liver may need them drained. This is typically done using a percutaneous abscess drainage, which is a minimally invasive procedure that uses imaging guidance to place a thin needle through the skin into the abscess to remove or drain the pus. These patients might also need to receive long-term antibiotics through an intravenous drip.
What else can Pseudoappendicitis be?
Acute appendicitis is often confused with acute yersiniosis, another type of illness. This condition is often mistaken for other health issues. These may include:
- Inflammatory bowel disease
- Meckel diverticulitis, a specific type of inflammation in the digestive tract
- Mesenteric lymphadenitis, an inflammation of the lymph nodes in the membrane that connects your bowel to the abdominal wall
- Ischemic colitis, which involves a decrease in blood supply to the colon
- And sigmoid diverticulitis, inflammation or infection in the last segment of the colon
Furthermore, doctors should not rule out the possibility of acute infectious gastroenteritis. This term refers to inflammation of the stomach and intestines due to an infection. Some examples include:
- Giardiasis
- Salmonellosis
- Shigellosis
- And Clostridioides difficile colitis
These conditions should be evaluated carefully to avoid misdiagnosis.
What to expect with Pseudoappendicitis
Pseudoappendicitis, a condition resembling appendicitis, is often caused by a mild form of infection known as acute yersiniosis. This condition is typically self-limiting, meaning it improves on its own over time. Generally, this conditions can be managed through non-invasive treatments such as intravenous (IV) fluid replacement and other supportive measures. Patients typically recover after 24 to 48 hours.
However, patients with a weakened immune system or those who have other health conditions may not have as smooth a recovery journey.
Possible Complications When Diagnosed with Pseudoappendicitis
While there are typically no lasting effects from acute yersiniosis, there may be some complications that do occur. These include erythema nodosum, a condition that causes red bumps on the skin, and reactive arthropathy, a type of joint inflammation. However, these complications often resolve on their own within six months. Some studies have also suggested that long-lasting yersiniosis could potentially lead to an overactive thyroid due to an autoimmune response, but this theory has yet to be confirmed.
Key Points:
- No permanent effects from acute yersiniosis
- Potential complications include erythema nodosum and reactive arthropathy
- Complications typically clear up within six months
- Unconfirmed theory linking long-term yersiniosis to autoimmune hyperthyroidism
Preventing Pseudoappendicitis
Yersinia enterocolitica, or Y enterocolitica, is a type of bacteria that is spread through what’s known as the fecal-oral route. This means it’s passed on when tiny particles of feces (or stool) are ingested, usually due to insufficient cleaning or hygiene practices. A good way to prevent getting infected with this bacteria is by strictly following the guidelines for safely handling food and maintaining good personal hygiene. Food should be carefully prepared and cooked properly to kill any bacteria, and frequent hand washing can help prevent the spread of bacteria.
