Pediatric Appendicitis Clinical Presentation

The classic history of anorexia and vague periumbilical pain, followed by migration of pain to the right lower quadrant (RLQ) and onset of fever and vomiting, is observed in fewer than 60% of patients. ^[2] If the appendix perforates, an interval of pain relief is followed by development of generalized abdominal pain and peritonitis. Although some patients progress in the classical fashion, some patients deviate from the classic model. Atypical presentations are common in neurologically impaired and immunocompromised patients, as well as in children who are already on antibiotics for another illness.

In patients with a retrocecal appendix, who constitute 15% of cases, signs and symptoms may not localize to the RLQ but instead to the psoas muscle, the flank or right upper quadrant. In other patients, the tip of the appendix is deep in the pelvis, and the signs and symptoms localize to the rectum or bladder resulting in pain with defecation or voiding.

Certain features of a child's presentation may suggest a perforated appendix. A child younger than 6 years with symptoms for more than 48 hours is much more likely to have a perforated appendix. The child may have generalized abdominal pain and may have a high heart rate and a temperature higher than 38°C.

A substantial risk of perforation within 24 hours of onset was noted (7.7%) in one study and was found to increase with duration of symptoms. While perforation was directly related to the duration of symptoms before surgery, the risk was associated more with prehospital delay than with in-hospital delay. ^[1]

Pain

All patients with appendicitis have abdominal pain, and many have anorexia; absence of both of these findings should place the diagnosis of appendicitis in question. A child who states that the ride to the hospital is painful when the vehicle hits bumps in the road suggests peritoneal irritation.

Acute onset of severe pain is not typical of acute appendicitis but is seen with acute ischemic conditions such as volvulus, testicular torsion, ovarian torsion, or intussusception. If the pain is initially located in the right lower quadrant, severe constipation should be considered. A high index of suspicion should be maintained when attributing pain to constipation, especially in a child who does not have a prior history of constipation. Many children do not report the early symptoms of appendicitis and only appreciate the pain when it localizes to the RLQ. In addition, children with a retrocecal appendicitis may have a delay in the appreciable pain, leading to a delay in presentation.

As appendicitis progresses, the pain migrates to the RLQ due to inflammation of the parietal peritoneum. This pain is more intense, continuous, and localized than the initial pain. This shift of pain rarely occurs in other abdominal conditions.

Atypical pain is common and occurs in 40-45% of patients. This includes children who initially have localized pain and those with no visceral symptoms. Pain on urination can be seen with pelvic appendicitis.

Nausea and vomiting

A unique feature of appendicitis is gradual onset of pain followed by vomiting. Vomiting first is more typical of gastroenteritis.

Generally, vomiting that occurs prior to pain is unusual. However, in patients with retrocecal appendices, particularly those that extend cephalad along the posterior surface of the right colon, inflammation of the appendix irritates the nearby duodenum, resulting in nausea and vomiting prior to the onset of RLQ pain.

Diarrhea

Significant diarrhea is atypical in appendicitis, and the physician should consider other diagnoses, while not ruling out appendicitis. In patients with an appendix in a pelvic location, inflammation of the appendix occasionally results in an irritative stimulation of the rectum. These patients often report diarrhea. However, upon closer questioning, such patients usually describe frequent, small-volume, soft stools rather than true diarrhea.

Fever

Most children with appendicitis are afebrile or have a low-grade fever and characteristic flushing of their cheeks. Severe fever is not a common presenting feature unless perforation has occurred, and even then it may still be rare. According to one study, vomiting and fever are more frequent findings in children with appendicitis than in children with other causes of abdominal pain.

The physical examination findings in children may vary depending on age. Irritability may be the only sign of appendicitis in a neonate. Older children often seem uncomfortable or withdrawn. They may prefer to lie still because of peritoneal irritation. Teenaged patients often present in a classic or near-classic fashion.

Examination of the child requires skill, patience, and warm hands. Initial and continued observation of the child is of critical importance. An ill-appearing quiet child who is lying very still in bed, perhaps with the legs flexed, is much more a cause for concern than a child who is laughing, playing, and walking around the room.

The examination should be thorough and start with areas other than the abdomen. Because lower lobe pneumonias can cause abdominal findings, a history of such should be elicited and a thorough chest examination performed. It is also important to exclude urinary tract infection (UTI) as a cause of abdominal pain.

Children vary in their ability to cooperate with the physical examination. It is important to tailor the physical examination to the child's age and developmental stage.

General examination

Patients’ general state should be observed before interacting with them. The patient’s state of activity or withdrawal may lend information into their condition. The child's gait may be observed if they are well enough to ambulate. A patient in obvious distress with abdominal pain gives the impression of an infectious process; however, other causes must be ruled out.

Cardiac and pulmonary examination

The findings on evaluation of the heart and lungs typically reflect the patient’s overall state more than they may suggest appendicitis. Patients are often dehydrated or in pain and may be tachycardic or tachypneic. Pediatric patients have great physiological reserves and may not show any general symptoms until they are very ill.

Abdominal examination

Full exposure of the abdomen is key. Before examining the abdomen, ask the child to point with one finger to the site of maximal pain. Begin palpation of the abdomen at a site distant to this, with the most tender area examined last. If the child is particularly anxious, palpation may be performed with a stethoscope.

Distracting questions concerning school and family members may be helpful to relieve anxiety during the examination. Observing the child's facial expressions during this questioning and palpating is critical.

Palpation of the abdomen should be performed with a gentle and light touch, searching for involuntary guarding of the rectus or oblique muscles. In early appendicitis, children may not have significant guarding or peritoneal signs. Younger children are much more likely to present with diffuse abdominal pain and peritonitis, perhaps because their omentum is not well developed and cannot contain the perforation.

Typically, maximal tenderness can be found at the McBurney point in the RLQ. A mass may be palpable in the RLQ if the appendix is perforated.

However, the appendix may lie in many positions. Patients with a medially positioned appendix may present with suprapubic tenderness. Patients with a laterally positioned appendix often have flank tenderness. Patients with a retrocecal appendix may not have any tenderness until appendicitis is advanced or the appendix perforates.

Presence of the Rovsing sign (pain in the RLQ in response to left-sided palpation or percussion) strongly suggests peritoneal irritation.

To assess for the psoas sign, place the child on the left side and hyperextend the right leg at the hip. A positive response suggests an inflammatory mass overlying the psoas muscle (retrocecal appendicitis).

Check for the obturator sign by internally rotating the flexed right thigh. A positive response suggests an inflammatory mass overlying the obturator space (pelvic appendicitis).

During the abdominal examination, try to avoid eliciting rebound tenderness. This is a painful practice and certainly destroys any trust that has been garnered during the examination. Peritonitis can be confirmed with gentle percussion over the right lower quadrant. Involuntary contraction of the abdominal wall musculature (involuntary guarding) and tenderness can be elicited with minimal stress or discomfort to the child.

Other methods can be used to establish that the patient has peritoneal irritation. Asking the patient to sit up in bed, cough, jump up and down, or bounce his or her pelvis off the bed while in the supine position may elicit pain in the presence of peritoneal irritation. Alternatively, other acceptable maneuvers are tapping the patient's soles and shaking the stretcher. A child with advanced appendicitis typically prefers to lie still due to peritoneal irritation.

Rectal examination

The digital rectal examination is often deferred but can be helpful in establishing the correct diagnosis, especially in sexually active adolescent girls. The patient should be told that the examination is uncomfortable but should not cause sharp pain. The caliber of the patient's anus should be taken into consideration, and smaller digits should be used for examining younger patients.

The rectal examination is particularly important in the child with a pelvic appendix, in whom the findings on the abdominal examination for appendicitis may be equivocal and indicative of peritoneal irritation.

Objective information to ascertain includes impacted stool or an inflammatory mass. Right-sided tenderness of the rectum is the classic finding in patients with pelvic appendicitis or in those with pus that pools in the pelvis from an inflamed appendix elsewhere in the abdomen.

Patients who are able to communicate should be asked if they have tenderness in different areas of the rectum. The rectal examination in a young child may have to be completely objective because they may not be able to communicate variations in tenderness or may have general discomfort from the examination.

Genitourinary examination

An external genitourinary (GU) examination is helpful to rule out testicular or scrotal tenderness in males and hematocolpos in pubertal girls.

Pelvic examination

A pelvic examination should be considered in sexually active adolescent girls to evaluate for tenderness (adnexal and/or cervical motion tenderness), masses, bleeding, or discharge.

Atypical findings

Becker et al found that 44% of patients diagnosed with appendicitis presented with 6 or more of the following atypical features ^[3] :

• No fever

• Absence of Rovsing sign

• Normal or increased bowel sounds

• No rebound pain

• No migration of pain

• No guarding

• Abrupt onset of pain

• No anorexia

• Absence of maximal pain in the RLQ

• Absence of percussive tenderness