Epidemiology

1. Highest incidence is 10-19 year olds. It is unusual under the age of 1 year.
2. The risk of perforation is greatest in 1-4 year olds and least in 10-14 year olds. 
3. Appendectomies are the most common emergency surgical procedures performed 
4. It is unusual in third world countries and there is a questionable relationship to high fiber diets.

1. Luminal obstruction is the usual initiating event
1. inspissated feces and fecalith
2. Hyperplasia of lymphoid tissue
3. mucous
4. foreign body
5. parasites
6. bacterial gastroenteritis
2. Obstruction is followed by continued production of mucous leading to distention and increased pressure. This is followed by venous congestion and ischemia, necrosis, and ulceration. Bacterial infection may also occur.
3. The initial distention leads to afferent stimuli of T8-T10 and subsequent epigastric and periumbilical pain.
4. After the necrosis of appendiceal wall there is peritoneal irritation and adherence to the parietal peritoneum. This causes a shift of the pain to the RLQ.
5. After perforation, the contamination may be confined to the RLQ or spread to the entire peritoneal cavity. 

1. Periumbilical pain preceding nausea, vomiting, and anorexia. Low grade fever often present and there may also be diarrhea. 
2. UTI symptoms may be present if the ureter or bladder is irritated.
3. Symptoms may be altered by the location of the appendix. 
1. retrocecal will cause flank and back pain
2. Pelvic location may produce increased urinary tract symptoms
3. With malrotation, the symptoms may be in the LUQ

1. The child will often walk into the office bent over, limping, and holding their right side.
2. The child will look ill and lay quietly
3. There is often diffuse abdominal tenderness.
4. There may be slight abdominal distention with initially increased and then decreased bowel sounds.
5. Point tenderness at McBurney's point which lies half-way between a line drawn from the umbilicus to the anterior iliac spine. 
6. Rebound tenderness
7. Rectal exam- value is questionable and should be done if suspect perforation and abscess.
8. Psoas sign- pain on flexion of the hip and Obturator sign which is increased pain on internal rotation of flexed thigh.
9. Check genitalia for possible incarcerated hernia or testicular pathology.

1. CBC may demonstrate an increased WBC count and RBC morphology should be checked
2. Urinalysis may have increased white cells

1. Plain film of abdomen may show fecalith, ileus pattern, evidence of constipation, or pneumonia.
2. Barium enema will show absence of filling of the appendix
3. Ultrasound and CT have been useful in certain situations.

1. Gastroenteritis- usually there is vomiting and/or diarrhea before the abdominal pain. There may be other ill contacts with similar symptoms.
2. Inflammatory bowel disease- usually symptoms are more chronic and history of poor weight and height gain
3. Testicular torsion and other intra-scrotal pathology
4. HSP
5. Ovarian cysts and twists
6. inflammatory disease
7. Intestinal obstruction

1. Surgical removal of the appendix
2. If the diagnosis is not clear, suggest observation in the hospital with frequent exam.
3. If there is a perforation, antibiotics should be started and may need surgical drainage of an abcess. The necessity of an appendectomy later is controversial.

1. Wound infection
2. Intra-abdominal abscess- occurs in 4-6% of perforations
3. Intestinal obstruction
4. Increased incidence of infertility in females who have had a perforation of the appendix secondary to fallopian tube obstruction and adhesions

1. Garcia Pena BM et al. Effect of Computed Tomography on Patient Management and Costs in Children with Suspected Appendicitis. Pediatrics. 1999; 104(3):440-446.
2. Irish MS et al. The Approach to Common Abdominal Diagnoses in Infants and Children. Pediatric Clinics of North America. 1998 45(4):729-772.
3. Silen, ML and Tracey, TF. The Right Lower Quadrant Revisited. Pediatric Clinics of North America. December 1993.
4. Ashcraft, Keith. Acute Abdominal Pain.  Pediatrics in Review November 2000
5. Garcia Pena BM et al. Effect of Imaging Protocol on Clinical Outcomes Among Pediatric Patients with Appendicitis. Pediatrics 2002 Vol. 110 No. 6 pg 1088
6. Paulson E.K. Suspected Appendicitis.  NEJM Vol 348 No 3. Page 236 January 16 2003
7. Kosloske A. The Diagnosis of Appendicitis in Children: Outcomes of a Strategy Based on Pediatric Surgical Evaluation. Pediatrics Jan 2004