Acute appendicitis is the inflammation of the appendix, a small organ attached to the large intestine, usually due to an obstruction between the two organs. The blockage may be due to a foreign body or undigested food. Infections can also lead to blockage of the appendix.

When the appendix becomes inflamed, due to a build-up of pressure within the organ, it causes pain in the abdomen. This is usually the first sign of a problem. Then the pain localizes to the right lower quadrant as the disease progresses. Common symptoms of acute appendicitis may include fever, loss of appetite and vomiting.

Appendicitis is an emergency, and patient should get medical help immediately. If you have appendicitis symptoms, you should go to an emergency room. The doctor will ask about your symptoms and your medical history, do a physical exam to check for abdominal tenderness, and may order blood and urine tests. A diagnosis of acute appendicitis is often confirmed with ultrasound to check whether the appendix is inflamed, and to rule out ovarian cysts or ectopic pregnancy in women. Doctors may also ask for a computed tomography (CT) scan.

 The surgical procedure known as an appendectomy is still the most common treatment for appendicitis. The appendectomy can be performed in two ways, laparotomy or laparoscopic. Laparotomy is the surgical removal of the appendix through an incision in the abdomen that can be 5-10 cm long. While a laparoscopic appendectomy involves making a few tiny cuts in the abdomen and inserting a tiny camera and surgical instruments. Recovery from a laparoscopic appendectomy is usually faster than with traditional surgery, and the scars are smaller. However, not everyone is a candidate for a laparoscopic appendectomy.

Appendicitis is usually treated with surgery and antibiotics. In the case of mild appendicitis, antibiotics may be administered alone to treat the condition. In general, antibiotics are prescribed even before surgery is carried out. If the patient heals before the surgery, then surgery is not required.

If appendicitis is not treated, the appendix can burst and cause potentially life-threatening infections. Complications may include inflammation of the abdominal lining, abscess and wound infection.

A healthy diet that includes fresh vegetables and fruits may help to decrease the risk. However, there is no sure way to prevent appendicitis. With treatment, people usually make a complete recovery from appendicitis, especially if the appendix does not rupture. In cases where the appendix ruptures, the death rate is higher, especially among the elderly.

Acute appendicitis is prevalent in all age groups of people. It is generally seen in patients 10-20 years old, and is more common in men and people with a family history of the disease.

Acute appendicitis is acute inflammation and infection of the vermiform appendix. The appendix is a blind-ending structure arising from the cecum that does not seem to have a specific purpose. Appendicitis causes pain in the lower right abdomen. However, in most people, pain begins around the navel and then moves. As inflammation worsens, appendicitis pain typically increases and eventually becomes severe.

The reason why the appendix becomes inflamed in the first place is not known in most cases. An obstruction of the appendiceal lumen that results in infection is the likely cause of appendicitis. This may be due to bits of indigestible food being delivered from the small intestine to the large intestine, or lymphoid hyperplasia that associated with various inflammatory and infectious disorders including Crohn disease, gastroenteritis, amebiasis, respiratory infections, measles, and mononucleosis. It may also be due to fecaliths, which form when calcium salts and fecal debris become layered around a nidus of inspissated fecal material located within the appendix. Obstruction of the appendiceal lumen has less commonly been associated with bacteria, parasites (eg, worms), foreign material, tuberculosis, and tumors. The bacteria may then multiply rapidly, behind the blockage in the dead end of the appendix, causing the appendix to become inflamed, swollen and filled with pus.

Acute appendicitis is generally seen in patients 10-20 years old, and is more common in men and people with a family history of the disease. A review has published in Scandinavian Journal of Surgery, in England, shows that positive family history increases the relative risk of being acute appendicitis nearly 3 times. Cystic fibrosis also seems to be associated with development of appendicitis. There is an increased risk of appendicitis associated with smoking, or second-hand smoking, in both adults and children.

The appendix is a small extension of the intestine that comes off the caecum. The appendix is usually located in the right lower side of the belly, and it is tubular in shape. It is normally about 5-10 cm long and quite narrow that has no known important function. Although, the appendix does contain some immune tissue, and it has been suggested that the appendix may play some part in defending the body against attack via the bowel, particularly in developing babies.

Obstruction of the narrow appendiceal lumen initiates the clinical illness of acute appendicitis. Once blockage of the appendix occurs, the appendix cannot empty the mucus and fluid that it makes. At the same time, intestinal bacteria within the appendix multiply, leading to the recruitment of white blood cells and the formation of pus and subsequent higher intraluminal pressure.

During the initial stage of appendicitis, the patient may feel only periumbilical pain due to the T10 innervation of the appendix. As the inflammation worsens, an exudate forms on the appendiceal serosal surface.

If appendiceal obstruction persists, intraluminal pressure rises ultimately above that of the appendiceal veins, leading to venous outflow obstruction. As a consequence, appendiceal wall ischemia begins, resulting in a loss of epithelial integrity and allowing bacterial invasion of the appendiceal wall.

Eventually, if not treated, the swollen appendix might perforate. Perforation results in the release of inflammatory fluid and bacteria into the abdominal cavity. This is very serious, as it can cause peritonitis, which is a serious infection of the membrane that lines the abdomen, or a collection of pus (an abscess) in the abdomen.

Early signs and symptoms:  When inflammation in the appendix begins, there is pain around the middle of the belly near the belly button. The child may have loss of appetite and feels like vomiting. The pain never completely goes away and becomes sharper with time. Most children with appendicitis have a fever of 38°-39° C.

Later signs and symptoms:  More than 24 hours after the pain starts, it moves to the right lower side of the belly. Sometimes, a child complains of right lower abdominal pain while walking, or refuses to stand up or walk due to pain. Younger than five years old children have a higher chance of having ruptured appendicitis because they may not be able to talk clearly about their symptoms. If the appendix ruptures, a high fever may be seen. There may be episodes of diarrhea.

The site of the pain may vary, depending on the age and the position of the appendix. In pregnant women, the pain may seem to come from the upper abdomen because the appendix is higher during pregnancy.

Appendicitis needs to be correctly and promptly diagnosed to avoid complications and possible mortality. Due to the wide range of clinical features, diagnosis can be difficult. To diagnose appendicitis, doctors usually take a history of the signs and symptoms and examine the abdomen. Tests and procedures used to diagnose appendicitis include:

1) Medical History

The doctor initially takes the patient’s medical history. The doctor enquires about the details of the abdominal pain such as the type and location of pain. For example, right lower side of abdomen that hurts with jumping, walking or other jarring movements may confirm the appendicitis. The doctor will ask whether the child may have nausea, vomiting, refusal to eat, fever or diarrhea.

2) Physical examination

Following the medical history, the doctor carries out a physical exam by putting pressure on specific parts of the abdomen. Based on the appropriate responses, the physician can make the diagnosis of appendicitis. Doctor may also look for abdominal rigidity and a tendency to stiffen the abdominal muscles in response to pressure over the inflamed appendix. Doctor may use a digital rectal exam where lubricated, gloved finger used to examine the lower rectum. In addition, a pelvic examination should be performed on all women with abdominal pain. Because many gynecologic conditions can mimic appendicitis.

3) Blood test

This allows the doctor to check for a high white blood cell count, which may indicate an infection. However, the WBC count and differential are only moderately helpful in confirming the diagnosis of appendicitis because of their low specificities. A more recently suggested laboratory test is determination of the C-reactive protein level. An elevated C-reactive protein level, greater than 0.8 mg per dL, is common in appendicitis, but studies disagree on its sensitivity and specificity also. An elevated C-reactive protein level in combination with an elevated WBC count and neutrophilia (97 to 100 percent), which is an increase of neutrophilic leukocytes in blood, are highly sensitive. Therefore, if all three of these findings are absent, the chance of appendicitis is low.

4) Urine test

 Doctor may want to have a urinalysis to make sure that a urinary tract infection or a kidney stone is not causing the pain. Acetone is normally found in urine in the condition of appendicitis.

5) Pregnancy Tests

 Women need to be checked to see if they are pregnant specially to avoid the use of harmful x-rays that may be used to diagnose appendicitis.

6) Abdominal X-ray

  A belly X-ray looks for clues regarding what may be causing the pain in general.

7) Ultrasound

 Ultrasound is very helpful to diagnose appendicitis. A probe is placed over the belly and sound waves are used to look at the appendix. A normal appendix is usually 6 mm in diameter or less. An inflamed appendix usually measures greater than 6 mm in diameter and is noncompressible. Other right lower quadrant conditions such as inflammatory bowel disease, cecal diverticulitis, Meckel's diverticulum, endometriosis and pelvic inflammatory disease can cause false-positive ultrasonography results.

8) Computed tomographic (CT) scan

 CT is most useful when the diagnosis is not clear or if ruptured appendicitis suspected. Unlike ultrasound, CT scans use radiation to obtain images. The child may be asked to drink a liquid that outlines the stomach and intestines. Sometimes, the contrast is given through the rectum. In some cases, an IV medicine is needed to help the CT get better pictures leading to a more accurate diagnosis.

9) Chest X-ray

Chest X-ray is very helpful to rule out pneumonia.

When the condition of appendicitis is not diagnosed or confirmed, it is termed as a misdiagnosis of appendicitis.

1) Surgery

Appendicitis treatment usually involves surgery to remove the inflamed appendix. The procedure known as appendectomy can be performed in two ways:

• Laparotomy: An open surgery using one abdominal incision about 5-10 cm long in the lower area to the right of the abdomen to remove the appendix.
• Laparoscopy: Laparoscopic surgeries are becoming more popular than open surgeries for appendectomies. During a laparoscopic appendectomy, the surgeon inserts special surgical tools and a video camera into the abdomen to remove the appendix. The usual number of incisions for laparoscopic surgery vary from one single port umbilical to three. Sometimes an extra cut is needed if the appendix is really ruptured and stuck. Smaller incisions, lesser post operative pain, faster recovery, and shorter duration of hospital stay are some of the benefits that laparoscopic procedures offer. Laparoscopy also has lower risks of wound infection and has the additional advantage of better cosmetic results. Nevertheless, laparoscopic surgery is not appropriate for everyone. If the appendix has ruptured and infection has spread beyond the appendix or an abscess may present, an open appendectomy may be needed, which allows the surgeon to clean the abdominal cavity. An open surgery is recommended for pregnant women, due to safety concerns with laparoscopic surgery.

When there is pus that is released due to a burst or ruptured appendix, the surgeon uses a tube to drain out the pus and treats the patient with antibiotics. Appendectomy can be performed several weeks later after controlling the infection, and the pus has been removed.

2) Antibiotics

Initiation of antibiotics upon diagnosis is critical to initiate treatment, slow the infectious process and prevent progression of a nonperforated appendix. In general, Antibiotic prophylaxis should be administered before every appendectomy. In the case of mild appendicitis, antibiotics may be administered to treat the condition. If the patient heals before the surgery, then surgery is not required. After treatment, patients are usually kept under observation for a short while. The most widely used antibiotic regimen is a penicillin based regimen such as piperacillin or ampicillin or the combination of ampicillin, clindamycin (or metronidazole), and gentamicin.  If a penicillin allergy exists, regimens including cephalosporins, aminoglycosides and clindamycin may be used.

3) Fluids are needed for patients with appendicitis. Since appendicitis causes loss of appetite, the patient may be dehydrated. Fluids are usually given through the vein.  

4) Analgesic medicine is also given to the patient to help make their belly pain better.

Appendicitis can cause serious complications, such as:

1) A ruptured appendix.

A rupture spreads infection throughout the abdomen causing peritonitis. Possibly life-threatening, this condition requires immediate surgery to remove the appendix and clean the abdominal cavity. Perforation of the appendix is more common among the elderly population due to an increased frequency of late and atypical presentation of appendicitis, delay in diagnosis, delayed decision for surgery and to the age-specific physiological changes. In addition, younger than five years old children have a higher chance of having ruptured appendicitis because they may not be able to talk clearly about their symptoms.

2) A pocket of pus that forms in the abdomen.

If the appendix bursts, abscess may develop. In most cases, a surgeon drains the abscess by placing a tube through the abdominal wall into the abscess. The tube is left in place for two weeks, beside antibiotics to clear the infection. Once the infection is clear, surgery required to remove the appendix.

3) Pylephlebitis:

Pylephlebitis is defined as septic thrombophlebitis of the portal vein or one of its tributaries, usually secondary to suppuration either in the region drained by the portal venous system or in structures contiguous to the portal vein.

There is no sure way to prevent appendicitis. A healthy diet that includes fresh vegetables and fruits may help to decrease the risk. In addition, some studies show that certain herbs and supplements may help to prevent appendicitis, strengthen the immune system, or help to recover faster from appendectomy surgery.

Generally, the prognosis of appendicitis is excellent. With treatment, people usually make a complete recovery from appendicitis, especially if the appendix does not rupture. In cases where the appendix ruptures, the death rate is higher, especially among the elderly.

Initiation of antibiotics represents the single most critical step in the treatment of acute appendicitis. Patients treated with antibiotics show a lower chance of complications following appendectomy, even if the appendectomy is delay to the next morning. Complications include infections of the wound, development of abscess, sepsis, blocked fallopian tube, inflamed lining of the abdomen and recurring cases of appendicitis when partially removing an appendix leaves a stump behind, which allows for recurrent appendicitis.

A Comparative Analysis study has published in the US journal PLOS one, 2016, shows that the incidence of appendicitis, since 1990, in North America and Europe ranged from 75 to 150 per 100,000 persons.

According to Hospital Episode Statistics has published by NHS, Appendicitis is the most common abdominal emergency and accounts for more than 40 000 hospital admissions in England every year.

In addition, a survey has published in American journal of epidemiology shows that appendicitis is most common between the ages of 10 and 20 years, but no age is exempt. A male preponderance exists, with a male to female ratio of 1.4:1.