Diagnosing Right Lower Quadrant Abdominal Pain in Children

Age-Specific Considerations

Children under 5 years present with atypical symptoms more frequently than older children, making diagnosis particularly challenging, and have a higher rate of perforated appendicitis due to delayed presentation and diagnosis 1
Classic symptoms such as periumbilical pain migrating to the right lower quadrant, anorexia, nausea, and vomiting are less reliable in children under 5 years 1

Appendicitis remains the primary concern in a four-year-old girl with right lower quadrant pain, despite being less common and more atypical in this age group, and is the most common surgical emergency causing RLQ pain in children overall 1
Intussusception is more common in this age group, typically presenting with intermittent colicky pain, vomiting, and potentially bloody stools 1
Mesenteric adenitis can mimic appendicitis, often following viral illness 1
Constipation is a frequent cause of abdominal pain in young children that can localize to the RLQ 1
Urinary tract infection/pyelonephritis can present with abdominal pain in young children who may not localize symptoms well 1
Ovarian torsion must be considered in any female with RLQ pain, though less common at age 4 2
Ovarian cyst can cause pain if large or ruptured 2

Urinalysis is essential to rule out urinary tract infection or nephrolithiasis 1
C-reactive protein may help assess severity of inflammation if available 1
Abdominal ultrasound is the initial imaging study of choice for pediatric patients with abdominal pain due to lack of radiation exposure, wide availability, and ability to identify multiple potential causes, with reasonable sensitivity and specificity for identifying appendicitis, intussusception, and other causes 1
If ultrasound results are equivocal or inconclusive and clinical suspicion remains high for a serious condition, CT scan with IV contrast should be considered, offering higher sensitivity and specificity for diagnosing appendicitis and other causes 1

The American College of Radiology recommends assessing for classic appendicitis symptoms, including periumbilical pain migrating to the right lower quadrant, anorexia, nausea, vomiting, fever, and rebound tenderness, in pediatric patients with right lower quadrant pain 3, 4
Clinical scoring systems, such as the Pediatric Appendicitis Score or Alvarado Score, can be used to stratify risk into low, intermediate, or high categories in pediatric patients with right lower quadrant pain 5, 3, 4

The American College of Radiology recommends ultrasound as the initial imaging modality of choice for pediatric patients with right lower quadrant pain, due to its zero radiation exposure, ability to identify appendicitis and other causes, and wide availability 5, 3, 4
If ultrasound is equivocal or non-diagnostic, MRI abdomen and pelvis without IV contrast is the preferred next step, due to its excellent diagnostic performance and lack of radiation exposure 5, 3
CT abdomen and pelvis with IV contrast should be considered only when MRI is not immediately available or contraindicated, or when clinical suspicion is very high and ultrasound is non-diagnostic 5, 3, 4

The American College of Radiology recommends proceeding to appendectomy as the standard treatment for confirmed appendicitis in pediatric patients 3, 4
For perforated appendicitis with abscess, percutaneous drainage followed by interval appendectomy with broad-spectrum antibiotics is a recommended treatment approach 3, 4, 6