What are the typical presentation and treatment of appendicitis?

Presentation and Treatment of Appendicitis

The classic presentation of appendicitis consists of periumbilical abdominal pain migrating to the right lower quadrant (RLQ), accompanied by loss of appetite, nausea or vomiting, with fever and leukocytosis present in about 50% of patients. 1

Clinical Presentation

Typical Presentation

• Initial periumbilical pain that migrates to the RLQ
• Anorexia (loss of appetite)
• Nausea and/or vomiting
• Low-grade fever
• Leukocytosis
• Right lower quadrant tenderness and guarding on examination

Atypical Presentations

• More common in certain populations:
  • Children under 5 years of age 1
  • Elderly patients 1
  • Pregnant women 2
• Elderly patients may present with:
  • More signs of peritonitis (abdominal distension, generalized tenderness)
  • Delayed presentation to medical care 1
  • Symptoms resembling bowel obstruction 1

Diagnostic Approach

Clinical Scoring Systems

• Alvarado Score and Appendicitis Inflammatory Response (AIR) score can help stratify risk 1
• Scoring systems are useful for excluding appendicitis in low-probability patients but should not be the sole basis for diagnosis 1
• Most beneficial for differentiating low-risk patients (who may not need imaging) from high-risk patients (who may proceed directly to surgical management) 1

Laboratory Tests

• Complete blood count (CBC) to assess for leukocytosis and left shift
• C-reactive protein (CRP) is included in the AIR score 1
• Laboratory tests alone have insufficient diagnostic accuracy, particularly in elderly patients 1

Imaging

• CT abdomen and pelvis is the primary diagnostic imaging modality with:
  • Sensitivity: 85.7-100%
  • Specificity: 94.8-100% 1
  • Negative appendectomy rate with preoperative CT: 1.7-7.7% 1
• CT findings suggestive of appendicitis:
  • Appendiceal dilatation (≥7 mm)
  • Wall thickening
  • Fat stranding
  • Presence of appendicolith 3
• Ultrasound is an alternative, particularly in children and pregnant women:
  • Sensitivity: approximately 87%
  • Specificity: approximately 89% 4, 5
• MRI can be used as an alternative, especially in pregnant patients 4

Treatment

Surgical Management

• Appendectomy remains the standard treatment for acute appendicitis 1, 3
• Laparoscopic appendectomy is preferred over open appendectomy when feasible 6
• Surgical consultation should be accomplished quickly for moderate to high-risk patients to reduce morbidity and mortality from perforation 6

Antibiotic Therapy

• Broad-spectrum antibiotics can be considered as primary treatment for uncomplicated appendicitis:
  • Success rate: approximately 70% 3
  • Common regimens include piperacillin-tazobactam monotherapy or combination therapy with cephalosporins/fluoroquinolones plus metronidazole 4, 3
• Patients with CT findings of appendicolith, mass effect, or dilated appendix >13 mm have higher risk of antibiotic treatment failure (approximately 40%) 3

Treatment Algorithm

1. Uncomplicated appendicitis without high-risk CT findings:

   • Either appendectomy or antibiotics can be considered as first-line therapy
   • Patient preference should be considered

2. Uncomplicated appendicitis with high-risk CT findings (appendicolith, mass effect, dilated appendix >13 mm):

   • Surgical management is recommended for patients fit for surgery

3. Complicated appendicitis (perforation, abscess):

   • Surgical management is typically required
   • In cases with abscess formation, percutaneous drainage followed by antibiotics may precede surgery 1

Complications

• Perforation occurs in 17-32% of patients with acute appendicitis 6
• Risk factors for perforation:
  • Delayed diagnosis
  • Extremes of age (very young children and elderly)
  • Delayed presentation to medical care 1, 4
• Complications of perforation include:
  • Abscess formation
  • Peritonitis
  • Sepsis
  • Increased morbidity and mortality 4

Special Considerations

• Appendicitis following blunt abdominal trauma is rare but should be considered in patients with right lower quadrant pain following trauma 7
• Preoperative management includes:
  • NPO status
  • IV fluid resuscitation
  • Broad-spectrum antibiotics
  • Adequate pain control 4

The diagnosis of appendicitis requires a combination of clinical assessment, laboratory tests, and imaging. Early diagnosis and appropriate treatment are essential to minimize complications, particularly perforation, which significantly increases morbidity and mortality.