Case Based Pediatrics For Medical Students and Residents
Department of Pediatrics, University of Hawaii John A. Burns School of Medicine
Chapter X.3. Appendicitis
Walton K.T. Shim, MD
January 2002

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A 7 year old girl presents to the emergency department with a chief complaint of abdominal pain for one day. Mid-abdominal pain started after lunch yesterday. This was followed by vomiting her lunch and a bowel movement, which did not relieve the pain. She did not feel like eating dinner and went to bed but slept fitfully. By morning the pain had increased and she vomited again. The pain has moved to the right lower quadrant and is increased by walking and coughing.

ROS: Non-contributory. No dysuria, cough or URI. No similar GI problem in the family. Pain remained constant in RLQ without radiation.

Exam: T 37.1, R 16, P 100, BP 150/70. She is alert, but subdued. HEENT Negative. Neck is supple. Chest is clear. Heart regular without murmur. Abdomen: Bowel sounds hypoactive with right lower quadrant tenderness and guarding. No organs or masses are felt. Right lower quadrant rebound tenderness is present. Genitalia: Normal; no hernias. Rectal: No masses or tenderness. She walks slowly and slightly hunched.

Lab: CBC WBC 14.0, 60% Segs, 15% Bands. UA 10-15 WBC, 15-20 RBC, no bacteria. Abdominal radiographs: Non-specific, no fecalith is seen.

Impression: Acute appendicitis

Surgery: Acute appendicitis; appendectomy performed

Pathology of appendix: Acute appendicitis

The recorded history of appendicitis demonstrates the evolution of our understanding and treatment of a disease process. It starts in the early 18th century and is summarized by Dr. Mark Ravitch in the chapter titled "Appendicitis" of the text Pediatric Surgery. It is recommended to all students of medicine (1). The Pathologist Reginald Fitz of Boston first described the condition of appendicitis in 1886 and in 1887, the Philadelphia surgeon T.G. Morton performed the first successful removal of an appendix which had been perforated. Charles McBurney immortalized "McBurney's point" when he described it in 1889 as the point of greatest tenderness located 1.5 to 2 inches (4 to 5 cm) from the anterior spine of the ileum on a line drawn between that point and the umbilicus.

It is estimated that 60,000 - 80,000 children are diagnosed with appendicitis annually (2), making it the most frequently performed emergency medical procedure in childhood. About 100 will die from complications (0.2%).

Obstruction of the lumen by impacted fecal material is the prime cause of appendicitis. This creates an increase in intraluminal pressure, edema and ultimately mucosal ulceration leading to infection and perforation. Obstruction from bacterial infections such as Yersinia, Shigella and Salmonella, from systemic viral infections, and from parasitic ascaris are rare causes. The earliest cases recorded were caused by ingested foreign bodies.

The diagnosis of acute appendicitis is a good example of critical thinking in medicine. It involves both inductive and deductive reasoning. It starts with a chief complaint, or the reason the patient comes to see the physician, followed by a probing evaluation and expansion of the chief complaint into what amounts to a history of symptoms surrounding the chief complaint or the present illness. We apply the recent mnemonic of S.O.A.P. (Subjective, Objective, Assessment, Plan) to the diagnosis and treatment of appendicitis.

S (subjective or symptoms): We find the subjective symptom of abdominal pain to be epigastric or mid-abdominal in location associated with anorexia and vomiting in most cases. This corresponds to the period of early obstruction and edema of the appendiceal lumen. This colic of the appendix, as with obstructive colicky pain of the entire intestinal tract is appreciated in the mid-abdomen or epigastrium. As the process of obstruction proceeds to edema and inflammation of the appendiceal wall and serosa, pain starts to localize in the dermatome overlying the infected appendix which is usually in the right lower quadrant. With a knowledge of pathophysiologic progression of the disease the physician/diagnostician/sleuth can round out the symptomatology with probative questions to elicit predictable symptoms associated with bowel inflammation such as the presence of an urge to defecate during the obstructive phase caused by the attempt of the intestine/appendix to expel the offending impacted material, anorexia and/or vomiting, pain with walking, and sudden pain relief with rupture only to have more intense symptoms recur as peritonitis becomes established.

At this point with the knowledge that abdominal pain can also be caused by genitourinary, respiratory, gynecological, lymphatic and neurological diseases, application of deductive reasoning should lead the diagnostician to ask whether or not the child has a respiratory infection with cough, sore throat or chest pain; whether or not there is radiation around the right flank or dysuria and groin pain indicating a urological cause; or in a girl, whether or not the pain radiates to the anterior right thigh indicating pain of ovarian origin. In post menarchal females, low abdominal pain occurring in mid-cycle may be caused by a ruptured ovarian follicle which is called mittelschmerz (literally, middle pain). Infected lesions of the right lower extremity may cause acute femoral and/or iliac adenitis and tenderness. Neurological causes such as nerve root pain should also be considered. Having eliminated these, concentrates the symptoms in the gastrointestinal tract. To rule out small bowel pathology, such as acute gastroenteritis, flu syndrome, Henoch-Schonlein purpura, chronic GI problems, the investigator must question the chronicity of the symptoms (regional ileitis), the involvement of family members (acute gastroenteritis), the presence of blood in the stools (intussusception and intestinal infection), etc. Once these are eliminated and the general health of the child has been established, the diagnostician can move on to the next phase which is observation.

O (objective or observations): It is of interest that colicky pain caused by obstruction of a hollow viscus is somewhat ameliorated by movement on writhing, whereas peritoneal pain is aggravated by movement. So we see that children with appendiceal inflammation causing peritoneal irritation tend to lie motionless and often say that the pain is aggravated by walking.

The next step in physical diagnosis and slightly more intrusive is auscultation with a stethoscope. As appendiceal inflammation progresses, the protective mechanism of the bowel causes it to become less active and bowel sounds are diminished until the belly becomes quiet with frank peritonitis. Normal or hyperactive bowel sounds should cast doubt on a diagnosis of appendicitis. While the examiner is evaluating bowel sounds, he or she should listen to the lower lobes of the chest as pneumonia of the lower lobes can cause inflammation of the lower thoracic dermatomes and be interpreted as abdominal pain.

Peritoneal pain can and should be elicited by palpation which should start in the LLQ and progress counterclockwise ending in the RLQ. If the examiner starts in the area of pain first, the child will start crying and make further evaluation difficult. The stiffening of the abdominal muscles to restrict deeper palpation is called voluntary guarding and is an important observation when limited to the RLQ. Further inflammation of the serosal surface leads to involuntary guarding or spasm indicating peritonitis.

Finally the physical examination portion of observation should conclude with an evaluation of groin tenderness to rule out a hernia or iliac adenitis as the cause for abdominal pain. A rectal examination may also be indicated in appendiceal perforation when a pelvic abscess is suspected.

A (assessment): Acute appendicitis is the most likely explanation for the findings since the patient's temperature is usually not elevated but the WBC is frequently slightly increased. There may be a left shift of the white count with bands being elevated even though the WBC is normal. The microscopic blood and white cells in the urine can be explained by an inflamed appendix overlying the right ureter causing transmural inflammation with blood and white cells in the urinalysis. This assessment is strengthened by the absence of dysuria and pain distribution in the area usually manifested in renal colic (right flank and groin).

The single most important observation which places acute appendicitis at the head of a list of differential diagnoses is RIGHT LOWER QUADRANT tenderness. Tenderness should be persistent and constant. Inconsistent tenderness casts doubt on the diagnosis of appendicitis. In addition to the laboratory tests of CBC with differential and a urinalysis I usually obtain an abdominal series looking especially for a RLQ fecalith, air/fluid levels, abnormal quantities of stool and signs of bowel obstruction and/or masses.

The CT scan should be used judiciously in cases when a diagnosis of appendicitis cannot definitely be made or ruled out. It is probably the single most important recent addition to the physician's armamentarium of diagnostic tools, but should not be used in place of a thorough history of symptoms and a good physical examination.

A repeat abdominal examination following an enema when much stool is present on rectal examination or abdominal radiographs may clarify the diagnostic dilemma. It is important to remember that initial symptoms frequently ameliorate with time.

P (plan): When the assessment leads to a diagnosis of acute appendicitis, immediate appendectomy should be scheduled. If perforation is suspected because of the severity of symptoms and the presence of peritonitis or evidence of perforation on CT scan, preoperative antibiotics should be administered and continued post-operatively.

Since these children have not eaten for a day or so and probably have vomited, dehydration and contraction of the extracellular space is an important consideration. Proper and adequate intravenous fluid administration should be given. If dehydration is severe and peritonitis is present, the bladder must be catheterized to monitor urine output as a reflection of adequacy of fluid administration. It is not unusual that three or four times the maintenance rate of electrolyte rich fluid is required for extracellular repletion and adequate blood volume support. Those patients with peritonitis should have particular encouragement to cough and deep breathe to prevent atelectasis and pneumonia as abdominal pain and distention cause elevation and splinting of the diaphragm leading to inadequate lung expansion and retention of secretions.


1. What is the difference between colicky and peritoneal pain?

2. Where is McBurney's point?

3. What two characteristics of the tenderness at McBurney's point make the diagnosis of appendicitis?

4. In cases of right lower quadrant pain and tenderness what is the second most frequent system implicated as its cause?

5. What is mittelschmerz?

Related x-rays

Ruptured appendix case: Yamamoto LG. Abdominal Pain and the Peritoneal Fat Margins. In: Yamamoto LG, Inaba AS, DiMauro R (eds). Radiology Cases In Pediatric Emergency Medicine, 1995, volume 3, case 19. Available online at:

Appendicitis case: Yamamoto LG. Post-Surgical Febrile Seizure and Vomiting. In: Yamamoto LG, Inaba AS, DiMauro R (eds). Radiology Cases In Pediatric Emergency Medicine, 1996, volume 4, case 10. Available online at:

Appendicoliths. Yamamoto LG, Goto CS. Appendicoliths. In: Yamamoto LG, Inaba AS, DiMauro R (eds). Radiology Cases In Pediatric Emergency Medicine, 1999, volume 6, case 18. Available online at:


1. Welch KJ, Randolph JG, Ravich MM, O'Neil JA Jr., Rowe MI (eds). Pediatric Surgery, 4th edition, 1986, Yearbook Medical Publishers, pp. 989-995.

2. Ashcraft KW, Holder TM (eds). Pediatric Surgery, 2nd edition, 1993, WB Saunders Company, pp. 470-477.

Answers to questions

1. Movement alleviates colicky pain but exacerbates peritoneal pain.

2. 4 to 5 cm (1.5 to 2 inches) cephalad on a line drawn between the anterior-superior iliac spine and the umbilicus.

3. Persistent and constant in nature.

4. Genitourinary.

5. Literally "middle pain" caused by a ruptured ovarian follicle which occurs approximately in mid-menstrual cycle.

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