Appendicitis

Gastroenterology (12%) Core Clinical Conditions

1B The Physician Associate is able to identify the condition as a possible diagnosis: may not have the knowledge/resources to confirm the diagnosis or to manage the condition safely, but can take measures to avoid immediate deterioration and refer appropriately.

Jump to content

Definition Aetiology Pathophysiology Risk factor Sign and Symptoms Investigations Management

Appendicitis is a medical condition characterised by the inflammation of the appendix, a small, finger-shaped organ attached to the large intestine in the lower right side of the abdomen. This condition often necessitates immediate medical attention due to the potential for severe complications if left untreated.
The appendix is believed to have minimal or no significant purpose in the human body's functioning. However, when it becomes obstructed, usually due to the accumulation of stool, a foreign object, or an infection, it can trigger inflammation and subsequent appendicitis. The obstruction typically results in a bacterial overgrowth, leading to infection.

According to the “obstruction theory”, an obstruction, often caused by the accumulation of hardened stool or a foreign object, blocks the narrow opening of the appendix. This blockage, in turn, leads to the increased pressure within the appendix, compromising its blood supply. This reduced blood flow renders the appendix vulnerable to bacterial overgrowth, resulting in inflammation and subsequent infection.

Another theory suggest that certain types of bacteria, particularly Escherichia coli (E. coli) and Bacteroides fragilis, play a pivotal role in the development of appendicitis. It is believed that these bacteria migrate from the large intestine into the appendix, where they multiply and initiate an immune response, triggering inflammation. However, the reason why these bacteria target the appendix specifically remains unclear.

Genetics may also contribute to the aetiology of appendicitis. Studies have shown that individuals with a family history of appendicitis are more prone to developing the condition, suggesting a genetic predisposition. However, the precise genes involved and the inheritance pattern remain elusive, warranting further investigation.

Diet and lifestyle in the aetiology of appendicitis cannot be overlooked. A diet low in fibre, high in processed foods, and lacking in fruits and vegetables has been associated with an increased risk of appendicitis. These dietary habits can lead to constipation, increasing the likelihood of faecal obstruction and subsequent inflammation.

Sedentary lifestyles and obesity have been linked to a higher risk of appendicitis, although the underlying mechanisms are not fully understood.

Obstruction

Appendicitis often begins with an obstruction of the appendix lumen, typically caused by a fecalith (a hardened piece of stool), lymphoid hyperplasia, or a tumor. This obstruction prevents normal drainage of mucus produced by the appendix, leading to an increase in intraluminal pressure.

Increased Intraluminal Pressure

The accumulation of mucus, combined with the continuous secretion of fluids by the appendix, causes an increase in intraluminal pressure. This pressure build-up leads to distention and stretching of the appendix wall.

Impaired Blood Circulation

As the pressure within the appendix rises, it starts to impede the blood flow, resulting in impaired circulation. The restriction of blood supply to the appendix impairs the delivery of oxygen and nutrients to its tissues, initiating a cascade of ischemic events.

Bacterial Overgrowth

The impaired blood circulation compromises the appendix's ability to fight off infection. Bacteria that are normally present in the appendix multiply rapidly due to the lack of adequate blood supply and invasion of mucus. This bacterial overgrowth worsens the inflammation.

Inflammation and Tissue Necrosis

The bacterial invasion triggers an inflammatory response within the appendix. The infected appendix becomes swollen, red, and warm. The body's immune system releases white blood cells and various inflammatory mediators to combat the infection. However, the compromised blood supply exacerbates the inflammation and leads to tissue necrosis.

Gangrene and Perforation

Prolonged inflammation and tissue necrosis can eventually lead to gangrene, where a portion of the appendix undergoes irreversible tissue death. Gangrene increases the risk of appendix rupture or perforation, allowing intestinal bacteria and inflammatory contents to spill into the abdominal cavity. Perforation significantly increases the severity of the condition, leading to a more complicated and potentially life-threatening situation such as peritonitis or abscess formation.

Spillage and Complications

Once the appendix ruptures, the bacterial contamination and inflammatory contents disseminate into the peritoneal cavity. This triggers an intense inflammatory response throughout the abdominal cavity, resulting in diffuse peritonitis. If abscesses form as a result, they may require drainage or surgical intervention to prevent further complications.

1. Age: Appendicitis can occur at any age, but it is most common in individuals between the ages of 10 and 30 years. Children and young adults are particularly susceptible to developing appendicitis, making age a significant risk factor.
2. Gender: Studies have shown that males are slightly more prone to appendicitis than females. Though the reasons for this gender disparity are not entirely clear, it suggests that males may have a slightly higher risk of developing appendicitis.
3. Genetics: There is evidence to suggest that genetics may play a role in the development of appendicitis. Individuals with a family history of appendicitis are more likely to develop the condition themselves. This genetic predisposition suggests a hereditary component to the risk of appendicitis.
4. Dietary Factors: While the exact relationship between diet and appendicitis is still not fully understood, some dietary factors have been associated with an increased risk. A low-fibre diet, for instance, may contribute to the development of appendicitis. Conversely, a diet rich in fruits, vegetables, and whole grains may help reduce the risk.
5. Obstruction: Appendicitis often occurs when the appendix becomes blocked or obstructed. Faecal matter, foreign objects, or enlarged lymphoid follicles can obstruct the opening of the appendix, leading to inflammation. Individuals who have a history of gastrointestinal issues or conditions that promote blockage may be at a higher risk of developing appendicitis.
6. Infections: Certain infections can increase the risk of inflammation in the appendix. For example, viral or bacterial infections in the gastrointestinal tract can cause inflammation that spreads to the appendix. Consequently, individuals with a history of gastrointestinal infections may have an elevated risk of appendicitis.
7. Prior Abdominal Surgery: Individuals who have previously undergone abdominal surgery, such as appendectomy, may be at a slightly higher risk of developing appendicitis. The surgical scarring or adhesion that occurs as a result of the previous procedure could potentially obstruct the appendix, leading to inflammation.
8. Smoking: Although the link is not yet fully understood, studies have suggested that smoking might be a risk factor for appendicitis. Smokers, particularly heavy smokers, may have a heightened risk compared to non-smokers.

1. Abdominal Pain
One of the primary symptoms of appendicitis is severe abdominal pain. Initially, the pain might be mild and located near the navel, but it gradually intensifies and shifts to the lower right side of the abdomen. This localised pain is often described as sharp or stabbing and can worsen with movement, coughing, or sneezing.
2. Loss of Appetite and Nausea
Appendicitis can cause a loss of appetite and feelings of nausea. Many individuals experiencing appendicitis may show a sudden disinterest in food and trigger waves of queasiness. This symptom is often accompanied by an overall feeling of discomfort or uneasiness.
3. Vomiting
Nausea and vomiting can also occur as a result of appendicitis. These symptoms may arise in conjunction with a loss of appetite, and the vomit may be bitter or contain bile. Persistent episodes of vomiting, without any relief, should be taken seriously and warrant medical attention.
4. Low-Grade Fever
A low-grade fever is commonly associated with appendicitis. The body's immune response to the inflammation caused by the infected appendix can cause a mild temperature elevation. Although the fever may not be extremely high, it should not be overlooked if observed alongside other symptoms.
5. Abdominal Tenderness
When the abdomen is palpated, tenderness and sensitivity can be felt over the area where the appendix is located. This is typically termed as "rebound tenderness" and is often present when the healthcare provider applies pressure to the abdomen and then releases it abruptly. If pressing on the abdomen causes sharp pain, it may indicate appendicitis.
6. Change in Bowel Movements
Another sign of appendicitis is a change in bowel movements. Patients may experience diarrhoea or constipation, or a fluctuation between the two. If accompanied by severe abdominal pain and other symptoms, this change in bowel habits can further support a diagnostic suspicion of appendicitis.

It is a medical emergency that requires immediate diagnosis and treatment to avoid serious complications.

The initial step in diagnosing appendicitis begins with a comprehensive patient history and physical examination. Ask about such as abdominal pain, loss of appetite, nausea, vomiting, and fever. The classic symptom of appendicitis is abdominal pain that starts around the belly button and migrates to the lower right side of the abdomen. This right lower abdominal tenderness is known as McBurney's point tenderness.

Hospital setting:

A full blood count (FBC) is often conducted to measure the levels of white blood cells (WBCs). Appendicitis typically causes an increase in WBC count, indicating an infection or inflammation in the body.

Imaging studies:

• Ultrasound and computed tomography (CT) scan.

• Magnetic resonance imaging (MRI).

• Immediate hospital admission

• Surgical intervention, which involves a surgical removal of the inflamed appendix, known as appendectomy, is the definitive treatment for appendicitis.

Jump to other topics below: