Appendicitis
Appendicitis is either infection or inflammation of the appendix, a small
tube-shaped organ that excretes mucus into the large intestine. The infection or
inflammation occurs when the opening of the tube becomes obstructed by very hard
fecal matter (stool), thick dried mucus or, in rare cases, parasites or tumors.
The most common cause of obstruction is hard stool.
Incidence
Acute appendicitis is the most
common surgical emergency in children and adolescents. Overall there are about
250,000 cases of appendicitis in the United States annually, and the majority
occur in children 6 to 10 years of age. Appendicitis affects males more often
than females (M:F ratio 3:2) and the lifetime risk for each group is 8.6% and
6.7%, respectively. Caucasians are affected more commonly than other racial
groups. Acute appendicitis occurs more frequently during the summer months.
Signs and symptoms
Appendicitis can affect any
age group. Although exceptionally rare in newborns and infants, acute
appendicitis does occasionally present at that young age, and diagnosis may be
extremely difficult and delayed. In slightly older children, the first signs and
symptoms are quite variable. Loss of appetite is usually the first symptom. Then
the young person frequently reports a dull, vague pain in the belly button area,
that then may gradually migrate to the right lower abdomen. Children typically
report a gradual increase in the pain. If the appendix is located in a place
other than where it is usually found, the pain may likewise vary in location.
For example, if the inflamed appendix is near the ureter or bladder, the child
may have urinary tract symptoms such as having to urinate frequently and/or
painful urination.
Nausea and mild vomiting usually develop within a few hours after the pain
appears. Diarrhea may also occur. Severe gastrointestinal (GI) symptoms that
develop prior to the onset of pain usually indicate a diagnosis other than acute
appendicitis. However, mild GI complaints such as indigestion or change in bowel
habits may sometime precede the pain.
Typically, patients with uncomplicated appendicitis have low-grade fever.
Temperatures above 101.5°F suggest that the appendix may have already burst.
Children with appendicitis avoid movement and tend to lie still in bed.
Frequently, they lie quietly on their sides or with their knees flexed. Children
with appendicitis sometimes walk with a limp favoring the right leg.
Left untreated, the tissues of the blocked appendix soon begin to die
(gangrene) and will perforate (burst), causing peritonitis, a serious,
potentially deadly, infection in the child's abdomen.
Diagnosis
- A good history and physical examination is the best way to begin
diagnosis. Followup examinations by the same person are perhaps the most
accurate diagnostic tool.
- Blood tests can be very helpful, too. A white blood cell count of more
than 10,000 is found in more than 90% of children with acute appendicitis.
- Urinalysis is helpful to differentiate the problem from a urinary tract
problem, which it can easily mimic.
- Abdominal ultrasound (which uses high-frequency sound waves to show images
of blood vessels, organs and tissues).
- Computed tomography (CT), a combination of x-rays and computer technology,
may also be useful. This is especially true in situations when the diagnosis
is unclear, such as in severely obese patients and patients presenting late
and suspected of having abscesses.
Treatment
Although spontaneous resolution
can sometimes occur, surgical removal of the appendix is still the best
treatment for patients suspected of having acute appendicitis. In uncomplicated
situations, the child typically receives preoperative and postoperative
antibiotics for only 24 hours and is usually discharged from the hospital in
24-48 hours. Most children resume normal activity and may return to school in as
little as 4-5 days.
For children who are brought for examination late (several days or weeks
after symptoms have begun), treatment is more complex and less standard. Some
may have immediate surgery while others are better served by receiving two to
three weeks of intravenous antibiotic therapy and/or CT-guided abscess drainage.
If surgery is not done initially, an elective interval appendectomy is usually
performed four to six weeks later but may not be totally necessary.
For perforated or gangrenous appendicitis, a five-day course of antibiotics
is often recommended; however, many surgeons stop postoperative antibiotics when
the recovering patient is free of fever and has a normal white blood cell
count.
Outcomes
Complication rates after appendectomy
vary with the severity of the appendicitis. Wound infection, overall observed in
five to ten percent of patients, is the most common complication.
Abscess formation and bowel obstruction occur in less than five percent of
patients and usually affect those with perforated appendicitis. The death rate
after perforation continues to fall but may be as high as approximately ten
percent based on some studies.