Definition

Appendicitis is an inflammation of the appendix,
which is the worm-shaped pouch attached to the cecum,
the beginning of the large intestine. The appendix has no
known function in the body, but it can become diseased.
Appendicitis is a medical emergency, and if it is left
untreated the appendix may rupture and cause a potentially
fatal infection.

Description

Appendicitis is the most common abdominal emergency
found in children and young adults. One person in
15 develops appendicitis in his or her lifetime. The incidence
is highest among males aged 10-14, and among
females aged 15-19. More males than females develop
appendicitis between puberty and age 25. It is rare in the
elderly and in children under the age of two.

The hallmark symptom of appendicitis is increasingly
severe abdominal pain. Since many different conditions
can cause abdominal pain, an accurate diagnosis of
appendicitis can be difficult. A timely diagnosis is important,
however, because a delay can result in perforation,
or rupture, of the appendix. When this happens, the
infected contents of the appendix spill into the abdomen,
potentially causing a serious infection of the abdomen
called peritonitis.

Other conditions can have similar symptoms, especially
in women. These include pelvic inflammatory
disease, ruptured ovarian follicles, ruptured ovarian
cysts, tubal pregnancies, and endometriosis. Various
forms of stomach upset and bowel inflammation may
also mimic appendicitis.

The treatment for acute (sudden, severe) appendicitis
is an appendectomy, surgery to remove the appendix.
Because of the potential for a life-threatening ruptured
appendix, persons suspected of having appendicitis are
often taken to surgery before the diagnosis is certain.

Causes and symptoms

The causes of appendicitis are not well understood,
but it is believed to occur as a result of one or more of
these factors: an obstruction within the appendix, the
development of an ulceration (an abnormal change in tissue
accompanied by the death of cells) within the appendix,
and the invasion of bacteria.

Under these conditions, bacteria may multiply within
the appendix. The appendix may become swollen and
filled with pus (a fluid formed in infected tissue, consisting
of while blood cells and cellular debris), and may
eventually rupture. Signs of rupture include the presence
of symptoms for more than 24 hours, a fever, a high
white blood cell count, and a fast heart rate. Very rarely,

the inflammation and symptoms of appendicitis may disappear
but recur again later.

The distinguishing symptom of appendicitis is pain
beginning around or above the navel. The pain, which
may be severe or only achy and uncomfortable, eventually
moves into the right lower corner of the abdomen.

There, it becomes more steady and more severe, and
often increases with movement, coughing, and so forth.
The abdomen often becomes rigid and tender to the
touch. Increasing rigidity and tenderness indicates an
increased likelihood of perforation and peritonitis.

Loss of appetite is very common. Nausea and vomiting
may occur in about half of the cases and occasionally
there may be constipation or diarrhea. The temperature
may be normal or slightly elevated. The presence of
a fever may indicate that the appendix has ruptured.

Diagnosis

A careful examination is the best way to diagnose
appendicitis. It is often difficult even for experienced
physicians to distinguish the symptoms of appendicitis
from those of other abdominal disorders. Therefore, very
specific questioning and a thorough physical examination
are crucial. The physician should ask questions,
such as where the pain is centered, whether the pain has
shifted, and where the pain began. The physician should
press on the abdomen to judge the location of the pain
and the degree of tenderness.

The typical sequence of symptoms is present in about
50% of cases. In the other half of cases, less typical patterns
may be seen, especially in pregnant women, older
patients, and infants. In pregnant women, appendicitis is
easily masked by the frequent occurrence of mild abdominal
pain and nausea from other causes. Elderly patients
may feel less pain and tenderness than most patients,
thereby delaying diagnosis and treatment, and leading to
rupture in 30% of cases. Infants and young children often
have diarrhea, vomiting, and fever in addition to pain.
While laboratory tests cannot establish the diagnosis,
an increased white cell count may point to appendicitis.
Urinalysis may help to rule out a urinary tract infection
that can mimic appendicitis.

Patients whose symptoms and physical examination
are compatible with a diagnosis of appendicitis are usually
taken immediately to surgery, where a laparotomy
(surgical exploration of the abdomen) is done to confirm
the diagnosis. In cases with a questionable diagnosis,
other tests, such as a computed tomography scan (CT)
may be performed to avoid unnecessary surgery. An
ultrasound examination of the abdomen may help to
identify an inflamed appendix or other condition tha
would explain the symptoms. Abdominal x-rays are not
of much value except when the appendix has ruptured.
Often, the diagnosis is not certain until an operation is
done. To avoid a ruptured appendix, surgery may be recommended
without delay if the symptoms point clearly to
appendicitis. If the symptoms are not clear, surgery may be
postponed until they progress enough to confirm a diagnosis.
When appendicitis is strongly suspected in a woman
of child-bearing age, a diagnostic laparoscopy (an
examination of the interior of the abdomen) is sometimes
recommended before the appendectomy in order to be
sure that a gynecological problem, such as a ruptured
ovarian cyst, is not causing the pain. In this procedure, a
lighted viewing tube is inserted into the abdomen
through a small incision around the navel.

A normal appendix is discovered in about 10-20% of
patients who undergo laparotomy, because of suspected
appendicitis. Sometimes the surgeon will remove a normal
appendix as a safeguard against appendicitis in the
future. During the surgery, another specific cause for the
pain and symptoms of appendicitis is found for about
30% of these patients.

Treatment

The treatment of appendicitis is an immediate
appendectomy. This may be done by opening the
abdomen in the standard open appendectomy technique,
or through laparoscopy. In laparoscopy, a smaller incision
is made through the navel. Both methods can successfully
accomplish the removal of the appendix. It is
not certain that laparoscopy holds any advantage over
open appendectomy. When the appendix has ruptured,
patients undergoing a laparoscopic appendectomy may
have to be switched to the open appendectomy procedure
for the successful management of the rupture. If a ruptured
appendix is left untreated, the condition is fatal.

Prognosis

Appendicitis is usually treated successfully by appendectomy.
Unless there are complications, the patient should
recover without further problems. The mortality rate in
cases without complications is less than 0.1%. When an
appendix has ruptured, or a severe infection has developed,
the likelihood is higher for complications, with slower
recovery, or death from disease. There are higher rates of
perforation and mortality among children and the elderly.

Prevention

Appendicitis is probably not preventable, although
there is some indication that a diet high in green vegetables
and tomatoes may help prevent appendicitis.