Appendicitis definition and facts
- The appendix is a small, worm-like, tubular appendage attached to the cecum of the colon.
- Appendicitis occurs when the appendix becomes blocked, and bacteria invade and infect the wall of the appendix.
- The most common complications of appendicitis are rupture, abscess, and peritonitis.
- The most common signs and symptoms of appendicitis in adults and children are
- Appendicitis usually is suspected on the basis of a patient's history and physical examination; however, a white blood cell count, urinalysis, abdominal X-ray, barium enema, ultrasonography, computerized tomography (CT)0 scan, and laparoscopy also may be helpful in diagnosis.
- Due to the varying size and location of the appendix and the proximity of other organs to the appendix, it may be difficult to differentiate appendicitis from other abdominal and pelvic diseases or even during the onset of labor during pregnancy.
- The treatment for appendicitis usually is antibiotics and appendectomy (surgery to remove the appendix).
- Complications of appendectomy include wound infection and abscess.
- Other conditions that can mimic appendicitis include Meckel's diverticulitis, pelvic inflammatory disease (PID), inflammatory diseases of the right upper abdomen (gallbladder disease, liver disease, or perforated duodenal ulcer), right-sided diverticulitis, ectopic pregnancy, and kidney diseases.
What is the appendix? Do we need it?
The appendix is a closed-ended, narrow, worm-like tube up to several inches in length that attaches to the cecum (the first part of the colon). (The anatomical name for the appendix, vermiform appendix, means worm-like appendage.) The inner lining of the appendix produces a small amount of mucus that flows through the open central core of the appendix and into the cecum. The wall of the appendix contains lymphatic tissue that is part of the immune system. Like the rest of the colon, the wall of the appendix also contains a layer of muscle, but the layer of muscle is poorly developed.
It is not clear if the appendix has an important role in the body in older children and adults. In young children it may have an immune function. There are no major, long-term health problems resulting from removing the appendix although a slight increase in some diseases has been noted, for example, Crohn's disease.
Quick GuideAppendix Pain? Appendicitis, Surgery, and More
Appendicitis Symptoms and Pain
The main symptom of appendicitis is pain. Most people say the initial pain of appendicitis occurs around the middle portion of the abdomen.
Another frequent symptom of appendicitis is loss of appetite that may worsen over time and can result in nausea and vomiting.
Other symptoms that can occur are:
- swelling of the abdomen,
- the inability to pass gas,
- constipation or diarrhea with gas, and
- a mild to moderate fever.
What is appendicitis? What causes it?
Appendicitis means inflammation of the appendix. It is thought that appendicitis begins when the opening from the appendix into the cecum becomes blocked. The blockage may be due to a build-up of thick mucus within the appendix or to stool that enters the appendix from the cecum. The mucus or stool hardens, becomes rock-like, and blocks the opening. This rock is called a "fecalith" (literally, a rock of stool). At other times, it might be that the lymphatic tissue in the appendix swells and blocks the opening. After the blockage occurs, bacteria which normally are found within the appendix begin to multiply and invade (infect) the wall of the appendix. The body responds to the invasion by mounting an attack on the bacteria, an attack called inflammation. If the symptoms of appendicitis are not recognized and the inflammation progresses, the appendix can rupture, followed by spread of bacteria outside of the appendix. The cause of such a rupture is unclear, but it may relate to changes that occur in the lymphatic tissue that lines the wall of the appendix, for example, inflammation that causes swelling and buildup of pressure within the appendix that causes it to rupture.
After rupture, infection can spread throughout the abdomen; however, it usually is confined to a small area surrounding the appendix by the surrounding tissues, forming a peri-appendiceal abscess.
Sometimes, the body is successful in containing ("healing") the appendicitis without surgical treatment if the infection and accompanying inflammation cause the appendix to rupture. The inflammation, pain, and symptoms also may disappear when antibiotics are used. This is particularly true in elderly patients. Patients then may come to the doctor long after the episode of appendicitis with a lump or a mass in the right lower abdomen that is due to the scarring that occurs during healing. This lump might raise the suspicion of cancer.
What does the appendix look like?
Appendicitis Illustration -Inflammation of the Appendix
What are the signs and symptoms of appendicitis?
Early signs and symptoms of appendicitis often are mild, consisting merely of a loss of appetite and/or nausea and a sense of not feeling well. There may not be even abdominal pain.
Nevertheless, as the course of the appendicitis progresses the main symptom becomes abdominal pain.
- The pain is at first diffuse and poorly localized, that is, not confined to one spot. (Poorly localized pain is typical whenever a problem is confined to the small intestine or colon, including the appendix.)
- The pain is so difficult to pinpoint that when asked to point to the area of the pain, most people indicate the location of the pain with a circular motion of their hand around the central part of their abdomen.
- With time, the pain may localize to the right lower abdomen, and the patient may be able to identify an exact location of the pain.
If not already present, a second symptom of appendicitis is loss of appetite which may progress to nausea and even vomiting. Nausea and vomiting also may occur later due to intestinal obstruction from the expanding inflammatory mass or abscess rather than from local inflammation.
As appendiceal inflammation increases, it may extend through the appendix to its outer covering and then to the lining of the abdomen, a thin membrane called the peritoneum. Once the peritoneum becomes inflamed, the character of the pain changes and then can be localized clearly to one small area. Generally, this area is between the front of the right hip bone and the belly button. The exact point is named after Dr. Charles McBurney-McBurney's point. If the appendix ruptures and infection spreads throughout the abdomen, the pain becomes diffuse again as the entire lining of the abdomen becomes inflamed.
Is there a test to diagnose appendicitis?
The diagnosis of appendicitis begins with a thorough history and physical examination. Patients often have an elevated temperature, and there usually will be moderate to severe tenderness in the right lower abdomen when the doctor pushes there. If inflammation has spread to the peritoneum, there is frequently rebound tenderness. Rebound tenderness is pain that is worse when the doctor quickly releases his or her hand after gently pressing on the abdomen over the area of tenderness.
White blood cell count
The white blood cell count usually becomes elevated with infection. In early appendicitis, before infection sets in, it can be normal, but most often there is at least a mild elevation even early in the process. Unfortunately, appendicitis is not the only condition that causes elevated white blood cell counts. Almost any infection or inflammation can cause the count to be abnormally high. Therefore, an elevated white blood cell count alone cannot be used to confirm a diagnosis of appendicitis.
Urinalysis is a microscopic examination of the urine that detects red blood cells, white blood cells and bacteria in the urine. Urinalysis usually is abnormal when there is inflammation or stones in the kidneys or bladder. The urinalysis also may be abnormal with appendicitis because the appendix lies near the ureter and bladder. If the inflammation of appendicitis is great enough, it can spread to the ureter and bladder leading to an abnormal urinalysis. Most patients with appendicitis, however, have a normal urinalysis. Therefore, a normal urinalysis suggests appendicitis more than a urinary tract problem.
Imaging studies to diagnosis appendicitis
An abdominal x-ray may detect the fecalith (the hardened and calcified, pea-sized piece of stool that blocks the appendiceal opening) that may be the cause of appendicitis. This is especially true in children. Nevertheless, the presence of a fecalith can occur without appendicitis.
An ultrasound is a painless procedure that uses sound waves to provide images to identify organs within the body. Ultrasound can identify an enlarged appendix or an abscess. Nevertheless, during appendicitis, an enlarged inflamed appendix or abscess can be seen in only 50% of patients. Therefore, not seeing the appendix during an ultrasound does not exclude appendicitis. Ultrasound also is helpful in women because it can exclude the presence of conditions involving the ovaries, Fallopian tubes and uterus (pelvic inflammatory disease, PID) that can mimic appendicitis.
A barium enema is an X-ray test in which liquid barium is inserted into the colon from the anus to fill the colon. This test can, at times, show an impression on the colon in the area of the appendix where the inflammation from the adjacent inflammation impinges on the colon. Barium enema also can exclude other intestinal problems that mimic appendicitis, for example Crohn's disease.
Computerized tomography (CT) scan
In patients who are not pregnant, a CT scan (a type of X-ray study) of the area of the appendix is useful in diagnosing appendicitis and peri-appendiceal abscesses as well as in excluding other diseases inside the abdomen and pelvis that can mimic appendicitis.
Laparoscopy is a surgical procedure in which a small fiberoptic tube with a camera is inserted into the abdomen through a small puncture made on the abdominal wall. Laparoscopy allows a direct view of the appendix as well as other abdominal and pelvic organs. If appendicitis is found, the inflamed appendix can be removed with the laparoscope. The disadvantage of laparoscopy compared to ultrasound and CT is that it requires a general anesthetic.
There is no one test that will diagnose appendicitis with certainty. Therefore, the approach to suspected appendicitis may include a period of observation, tests as previously discussed, or surgery.
Which specialties of doctors treat appendicitis?
A person with appendicitis may be seen first by generalists such as family practitioners, internists, and pediatricians, but he or she also may first be seen by surgeons, particularly general surgeons. Once appendicitis is suspected, a general surgeon almost always in called in consultation and in case surgery is necessary.
Why can it be difficult to diagnose appendicitis?
It can be difficult to diagnose appendicitis. The position of the appendix in the abdomen may vary. Most of the time the appendix is in the right lower abdomen, but the appendix, like other parts of the intestine, has a mesentery. This mesentery is a sheet-like membrane that attaches the appendix to other structures within the abdomen. If the mesentery is large, it allows the appendix to move around. In addition, the appendix may be longer than normal. The combination of a large mesentery and a long appendix allows the appendix to dip down into the pelvis (among the pelvic organs in women). It also may allow the appendix to move behind the colon (called a retro-colic appendix). In either case, inflammation of the appendix may appear to be more like the inflammation of other organs, for example, of a woman's pelvic organs.
The diagnosis of appendicitis also can be difficult because other inflammatory problems may mimic appendicitis, for example, right side diverticulitis. Therefore, it is common to observe patients with suspected appendicitis for a period of time to see if the problem will resolve on its own or develop characteristics that more strongly suggest appendicitis or, perhaps, another condition.
What is stump appendicitis?
When the appendix is removed surgically, a small portion may be left behind. This piece of appendix may become inflamed and is prone to develop all of the complications of appendicitis. Thus, it is possible for individuals who have had their appendix "removed" to develop another episode of appendicitis. Stump appendicitis is treated similarly to appendicitis with an intact (surgically unremoved) appendix. It is important to consider early and diagnose stump appendicitis since inadequate diagnosis and treatment can result in a rupture of the inflamed stump.
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What are the complications of appendicitis?
The most frequent complication of appendicitis is perforation. Perforation of the appendix can lead to a peri-appendiceal abscess (a collection of infected pus) or diffuse peritonitis (infection of the entire lining of the abdomen and the pelvis). The major reason for appendiceal perforation is delay in diagnosis and treatment. In general, the longer the delay between diagnosis and surgery, the more likely is perforation. The risk of perforation 36 hours after the onset of symptoms is at least 15%. Therefore, once appendicitis is diagnosed, surgery should be done without unnecessary delay if the patient does not improve with antibiotics alone.
A less common complication of appendicitis is blockage or obstruction of the intestine. Blockage occurs when the inflammation surrounding the appendix compresses the intestine, and this prevents the intestinal contents from passing. If the intestine above the blockage begins to fill with liquid and gas, the abdomen distends, and greater nausea and vomiting may occur. It then may be necessary to drain the contents of the intestine through a tube passed through the nose and esophagus and into the stomach and intestine.
A feared complication of appendicitis is sepsis, a condition in which infecting bacteria enter the blood and travel to other parts of the body. This is a very serious, even life-threatening complication. Fortunately, it occurs infrequently.
What other conditions can mimic appendicitis?
The surgeon faced with a patient suspected of having appendicitis always must consider and look for other conditions that can mimic appendicitis. Among the conditions that mimic appendicitis are:
- Meckel's diverticulitis. A Meckel's diverticulum is a small outpouching of the small intestine which usually is located in the right lower abdomen near the appendix. The diverticulum may become inflamed or even perforate (break open or rupture). If inflamed and/or perforated, it usually is removed surgically.
- Pelvic inflammatory disease (PID). The right Fallopian tube and ovary lie near the appendix. Sexually active women may contract infectious diseases that involve the tube and ovary. Usually, antibiotic therapy is sufficient treatment, and surgical removal of the tube and ovary are not necessary.
- Inflammatory diseases of the right upper abdomen. Fluids from the right upper abdomen may drain into the lower abdomen where they stimulate inflammation and mimic appendicitis. Such fluids may come from a perforated duodenal ulcer, gallbladder disease, or inflammatory diseases of the liver, for example, a liver abscess.
- Right-sided diverticulitis. Although most diverticuli are located on the left side of the colon, they occasionally occur on the right side. When a right-sided diverticulum ruptures it can provoke inflammation that mimics appendicitis.
- Kidney diseases. The right kidney is close enough to the appendix that inflammatory problems in the kidney-for example, an abscess-can mimic appendicitis.
- Ectopic pregnancy: Although it usually is easy to differentiate between a normal intrauterine pregnancy, if the fetus implants in the fallopian tube or elsewhere instead of the uterus, the symptoms may mimic appendicitis.
What is the treatment for appendicitis?
Once a diagnosis of appendicitis is made, an appendectomy usually is performed. Antibiotics almost always are begun prior to surgery and as soon as appendicitis is suspected.
There is a small group of patients in whom the inflammation and infection of appendicitis remain mild and localized to a small area. The body is able not only to contain the inflammation and infection but to resolve them as well. These patients usually are not very ill and improve during several days of observation. This type of appendicitis is referred to as "confined appendicitis" and may be treated with antibiotics alone. The appendix may or may not be removed at a later time. There is still some controversy, however, about leaving the healed appendix in place since appendicitis can recur.
On occasion, a person may not see their doctor until appendicitis with rupture has been present for many days or even weeks. In this situation, an abscess usually has formed, and the appendiceal perforation may have closed over. If the abscess is small, it initially can be treated with antibiotics; however, an abscess usually requires drainage. A drain (a small plastic or rubber tube) usually is inserted through the skin and into the abscess with the aid of an ultrasound or CT scan that can determine the exact location of the abscess. The drain allows pus to flow from the abscess out of the body. The appendix may be removed several weeks or months after the abscess has resolved. This is called an interval appendectomy and is done to prevent a second attack of appendicitis.
How is an appendectomy done?
- During an appendectomy, an incision two to three inches in length is made through the skin and the layers of the abdominal wall over the area of the appendix.
- The surgeon enters the abdomen and looks for the appendix which usually is in the right lower abdomen.
- After examining the area around the appendix to be certain that no additional problem is present, the appendix is removed. This is done by freeing the appendix from its mesenteric attachment to the colon, cutting the appendix from the colon, and sewing over the hole in the colon. If an abscess is present, the pus can be drained with drains that pass from the abscess and out through the skin.
- The abdominal incision then is closed.
New techniques for removing the appendix involve the use of the laparoscope. The laparoscope is a thin telescope attached to a video camera that allows the surgeon to inspect the inside of the abdomen through a small puncture wound (instead of a larger incision). If appendicitis is found, the appendix can be removed with special instruments that can be passed into the abdomen, just like the laparoscope, through small puncture wounds. The benefits of the laparoscopic technique include less post-operative pain (since much of the post-surgery pain comes from the incisions) and a speedier return to normal activities. An additional advantage of laparoscopy is that it allows the surgeon to look inside the abdomen to make a clear diagnosis in cases in which the diagnosis of appendicitis is in doubt. For example, laparoscopy is especially helpful for menstruating women in whom a rupture of an ovarian cyst may mimic appendicitis.
If the appendix is not ruptured (perforated) at the time of surgery, the patient generally is sent home from the hospital after surgery in one or two days. Patients whose appendix has perforated are sicker than patients without perforation, and their hospital stay often is prolonged (four to seven days), particularly if peritonitis has occurred. Intravenous antibiotics are given in the hospital to fight infection and assist in resolving any abscess.
Occasionally, the surgeon may find a normal-appearing appendix and no other cause for the patient's problem. In this situation, the surgeon will usually remove the appendix. The reasoning in these cases is that it is better to remove a normal-appearing appendix than to miss, and not treat appropriately, an early or mild case of appendicitis. In addition, if patients have "appendicitis" like pain again, the doctor will know that the appendix has been removed, and the diagnosis of appendicitis is not possible.
Quick GuideAppendix Pain? Appendicitis, Surgery, and More
What are the complications of appendectomy?
The most common complication of appendectomy is infection of the wound, that is, of the surgical incision. Such infections vary in severity from mild, with only redness and perhaps some tenderness over the incision, to moderate, requiring only antibiotics, to severe, requiring antibiotics and surgical treatment. Occasionally, the inflammation and infection of appendicitis are so severe that the surgeon will not close the incision at the end of the surgery because of concern that the wound is already infected. Instead, the skin closing is postponed for several days to allow the infection to subside with antibiotic therapy and make it less likely for infection to occur within the incision. Wound infections are less common with laparoscopic surgery.
Another complication of appendectomy is an abscess, a collection of pus in the area of the appendix or pelvis. Although abscesses can be drained of their pus surgically, there are also non-surgical techniques, as previously discussed.
Are there long-term consequences of appendectomy?
It is not clear if the appendix has an important role in the body in older children and adults. There are no major, long-term health problems resulting from removing the appendix although a slight increase in some diseases has been noted, for example, Crohn's disease.
What is new about appendicitis?
Recently, it has been hypothesized that some episodes of appendicitis-like symptoms, especially recurrent symptoms, may be due to an increased sensitivity of the intestine and appendix from a prior episode of inflammation. That is, the recurrent symptoms are not due to recurrent episodes of inflammation. Rather, prior inflammation has made the nerves of the intestines and appendix or the central nervous system that innervate them more sensitive to normal stimuli, that is, with stimuli other than inflammation. This will be a difficult, if not impossible, hypothesis to confirm.
Medically Reviewed on 7/3/2017
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.