Appendicitis: Introduction, Incidence and Symptoms


What is Appendicitis?

Acute appendicitis is an inflammation of the appendix. The appendix is a small pouch that extends from the large intestine on the lower right side of the body, and is not known to perform any function. 

Inflammation of the appendix occurs when it becomes obstructed due to accumulation of stool, tumours or diseased due to infection by viruses, bacteria or parasites in the digestive tract. As the appendix becomes increasingly engorged, it will irritate the lining of the abdominal wall, known as the peritoneum. This then causes characteristic sharp pain in the right lower part of the abdomen.

Appendicitis can progress quickly to appendix rupture within 24 to 72 hours, allowing stool and infectious material to leak into the abdomen, causing a serious infection known as peritonitis. Thus, appendicitis is an emergency mostly requiring surgery to remove the appendix, which is called an appendectomy. 

Epidemiology – Incidence and Distribution

Appendicitis is one of the most common surgical emergencies globally. In the US, it  occurs in 7% of the population, with an incidence of 1.1 cases per 1000 people per year. 

Higher intake of dietary fibre has been associated with lower rates of appendicitis. Dietary fibre decreases the viscosity of feces and bowel transit time, thus preventing the accumulation of stool and consequent obstruction of the appendix. Compared to Western countries, the incidence of acute appendicitis is lower in Asian and African countries, probably due to differing dietary habits i.e. higher fibre intake in these areas. 

Males have a marginally higher lifetime incidence of developing acute appendicitis (8.6%) compared to females (6.7%). Appendicitis can occur at any age, but most commonly affects children and young adults. The age group of 10 to 19 years old is at higher risk. Younger children have higher rates of ruptured appendix, with reported rates of 50-85%. The average age that most appendectomies are performed is 22 years.

What are the symptoms of appendicitis?

Abdominal pain is the most common symptom and is reported in nearly all confirmed cases of appendicitis. The clinical presentation of acute appendicitis is described as a constellation of the following classic symptoms:

  •  Right lower quadrant  abdominal pain
  •  Nausea and vomiting
  •  Anorexia (weight loss)
  •  Fever

In many patients, initial features are atypical or nonspecific and can include:

  • Indigestion
  • Flatulence
  • Bowel irregularity
  • Diarrhoea

There are also many other conditions with similar symptoms to appendicitis, e.g. gastroenteritis (infection and inflammation of the digestive system), Crohn’s disease (inflammatory bowel disease), urinary tract infection or kidney stones.

As such, it is best to seek medical attention soonest for accurate diagnosis and appropriate treatment should you experience the symptoms listed above. 

How is appendicitis diagnosed?

If you have appendicitis, your physician might be able to diagnose it just by doing a physical examination. He or she can learn a lot about your condition by pressing on your belly and talking with you about your symptoms. If your physician is not certain after this, he or she can do other tests – 

1. Computed tomography (CT) findings

The following findings suggest acute appendicitis on standard abdominal computed tomography (CT) scanning with contrast including enlarged appendiceal diameter >6 mm with an occluded lumen

2. Ultrasound findings

The most accurate ultrasound finding for acute appendicitis is an appendiceal diameter of >6 mm.

3. Plain radiograph (X-Ray) findings

Plain radiographs are usually not helpful for establishing the diagnosis of appendicitis 

4. Magnetic resonance imaging (MRI)

Magnetic resonance imaging (MRI) can assist with the evaluation of acute abdominal and pelvic pain during pregnancy. 

How is appendicitis treated?

The main treatment for appendicitis is surgery to remove the appendix. This appendectomy can be done in 2 ways:

1. Open surgery – During open surgery, the surgeon makes a cut near the appendix that is big enough to pull the appendix through.

2. Laparoscopic surgery – During laparoscopic surgery, the surgeon makes a few cuts that are much smaller than those used in open surgery. Then he or she inserts long, thin tools into the belly. One of the tools has a camera on the end, which sends pictures to a TV screen. The surgeon can look at the image on the screen to know where to cut and what to remove. The surgeon then uses these long tools to do the surgery.

If your appendix has burst, your surgery will be more complicated. Your surgeon will need to clean away the material that has spilt out from the ruptured appendix into the abdominal cavity. As a result, your cuts might be larger or you might spend more time in surgery.

What are the risks after surgery?

  • Pus formation at surgical incision site
  • Wound infection
  • Other rare complications e.g. intestinal peristalsis, injuries to internal organs during surgery
  • Infection of the abdominal cavity and bowel obstruction.

What are the Dos and Don’ts after Appendix surgery?

You should:

  • Drink plenty of fluids to help prevent constipation. 
  • Have plenty of rest at home

You should not:

  • Lift heavy objects
  • Climb stairs lest you strain your abdominal muscles.

Can appendicitis be treated without surgery?

Yes. If your appendix has not ruptured, it is possible to treat appendicitis with just antibiotics. However, without surgery, there is a chance your appendicitis will recur. So surgery is still the best treatment in most cases.

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