What is the diagnosis and management for a 7-year-old child presenting with intermittent left lower quadrant (LLQ) abdominal pain, nausea, vomiting, and subjective fever, who has a low appetite, discomfort when lying on their stomach, and a history of family members with a cold, but denies constipation, diarrhea, and sick contacts?

Diagnosis and Management of Left Lower Quadrant Abdominal Pain in a 7-Year-Old

This 7-year-old requires urgent imaging with ultrasound as the first-line modality to evaluate for appendicitis, despite the atypical left-sided location, followed by CT if ultrasound is inconclusive, as appendicitis can present with atypical pain location and remains the most critical surgical emergency to exclude in this age group. 1

Clinical Assessment and Differential Diagnosis

Why Appendicitis Must Be Considered First

• Appendicitis is the most common abdominal surgical emergency in children, accounting for approximately 70,000 cases annually in the United States, and represents the most critical diagnosis not to miss due to potential morbidity from perforation 1
• Classic symptoms are frequently absent in pediatric patients, particularly in children under 5 years, who present with atypical symptoms more often than older children and adults 1
• The combination of nausea, vomiting, and abdominal pain is the classic presentation of acute appendicitis, even when pain location is atypical 2
• Left lower quadrant pain does not exclude appendicitis—a retrocecal or malpositioned appendix can cause pain in unusual locations, and children may have difficulty localizing pain accurately 3, 4

Key Clinical Features in This Case

• Pain preceding vomiting is a red flag for surgical pathology rather than medical gastroenteritis, where vomiting typically precedes pain 3, 4
• The 4-day duration with intermittent symptoms and discomfort lying on stomach suggests peritoneal irritation, which warrants urgent evaluation 4
• Subjective fever with nausea and low appetite are consistent with appendicitis, though these symptoms are nonspecific 1, 2
• Recent family cold exposure may be coincidental—viral prodrome can occasionally precede appendicitis, but this should not distract from surgical evaluation 3

Immediate Diagnostic Approach

First-Line Imaging: Ultrasound

Obtain abdominal ultrasound immediately as the initial imaging modality for this pediatric patient, as it avoids radiation exposure and is the recommended first-line test in children with suspected appendicitis 1

• Ultrasound should be performed with graded compression technique to displace overlying bowel gas and bring the appendix closer to the transducer 1
• The examination should evaluate all potential appendix locations, not just the right lower quadrant, given the left-sided pain presentation 1
• Ultrasound accuracy is operator-dependent and may be limited by body habitus or bowel gas, but remains the appropriate initial test in children 1

Second-Line Imaging: CT if Ultrasound Inconclusive

If ultrasound is negative or inconclusive but clinical suspicion remains, proceed immediately to contrast-enhanced CT abdomen and pelvis 1, 2

• CT achieves sensitivity of 85.7-100% and specificity of 94.8-100% for appendicitis diagnosis 2, 5, 6
• CT with IV contrast (without oral contrast) is preferred to avoid delays associated with oral contrast administration while maintaining diagnostic accuracy of 90-100% sensitivity 5, 6
• CT will also identify alternative diagnoses including mesenteric adenitis (common after viral illness), intussusception, ovarian pathology in females, or other inflammatory conditions 6, 4

Essential Laboratory Testing

Order complete blood count and C-reactive protein immediately 2, 6

• CRP levels are significantly higher in appendicitis versus other etiologies, and normal inflammatory markers have 100% negative predictive value for excluding appendicitis 2, 6
• Obtain basic metabolic panel to assess for dehydration and electrolyte abnormalities from vomiting 6
• Consider urinalysis to exclude urinary tract infection, which can occasionally present with abdominal pain 4

Physical Examination Red Flags

Critical Signs to Assess

Examine specifically for signs of peritoneal irritation and surgical abdomen 3, 4

• Test for psoas sign (pain with hip extension or flexion), which suggests appendicitis or retroperitoneal pathology and may explain the discomfort lying on stomach 2, 6
• Assess for involuntary guarding, rigidity, rebound tenderness, and decreased bowel sounds—these findings indicate acute surgical abdomen requiring urgent surgical consultation 3, 4
• Evaluate for Rovsing sign (pain in right lower quadrant with palpation of left lower quadrant) and obturator sign, which support appendicitis diagnosis 4
• The patient's discomfort lying on stomach is concerning for peritoneal irritation and should not be dismissed 4

Immediate Management

Supportive Care While Awaiting Imaging

Provide IV fluid resuscitation for dehydration from 4 days of decreased oral intake and vomiting 2

Administer antiemetics for symptom control:

• Ondansetron can be given to children >4 years of age to facilitate tolerance of oral rehydration and reduce vomiting 1
• Ondansetron reduces immediate need for hospitalization or IV rehydration in pediatric gastroenteritis, though it may increase stool volume 1

Hold off on pain medication until surgical evaluation is complete if appendicitis is suspected, as this may mask evolving peritoneal signs 3

Surgical Consultation Timing

Obtain urgent surgical consultation if imaging confirms appendicitis or if high clinical suspicion persists despite negative imaging 2, 6

• Standard treatment for confirmed appendicitis is appendectomy 1, 2
• If perforated appendicitis with abscess is found, consider percutaneous drainage followed by delayed surgery 1, 2
• If imaging is negative but clinical suspicion remains high, diagnostic laparoscopy may be indicated, as it has both diagnostic and therapeutic value 2, 6

Alternative Diagnoses to Consider

If Appendicitis is Excluded

Mesenteric adenitis is common after viral illness and can mimic appendicitis with abdominal pain, fever, and nausea 4

• Usually self-limited and managed supportively
• CT or ultrasound shows enlarged mesenteric lymph nodes without appendiceal inflammation

Gastroenteritis is the most common medical cause of acute abdominal pain in children 3

• However, vomiting typically precedes pain in gastroenteritis (opposite of this case) 3
• The 4-day duration without diarrhea makes simple gastroenteritis less likely

Constipation should be considered despite patient denial 4

• Can cause left lower quadrant pain and nausea
• Abdominal radiograph may show stool burden if clinical suspicion is high

Intussusception is less common at age 7 but possible 7

• Classic triad of abdominal pain, hematochezia, and palpable mass is rarely complete
• Ultrasound would identify this if present

Critical Pitfalls to Avoid

Do not dismiss this as viral gastroenteritis based on family cold history—the pain-before-vomiting pattern and 4-day duration with peritoneal signs warrant imaging 3, 4

Do not delay imaging waiting for symptoms to "declare themselves"—appendicitis in children can progress rapidly to perforation, especially in younger age groups 1

Do not rely solely on right lower quadrant pain for appendicitis diagnosis—atypical presentations are common in pediatric patients, and pain localization may be inaccurate 1, 3

Do not use clinical scoring systems alone (Pediatric Appendicitis Score, Alvarado Score) to exclude appendicitis when clinical concern exists—these are best used to identify low-risk patients who may not need imaging 1

Do not give loperamide or antimotility agents to children <18 years of age with acute abdominal pain, as this can mask surgical pathology and is contraindicated in this age group 1