What are the clinical examinations for acute appendicitis?

Clinical Examination of Acute Appendicitis

Use clinical findings systematically to risk-stratify patients with suspected appendicitis, combining specific symptoms, physical examination signs, and laboratory tests to guide decisions about imaging and surgical consultation. 1

Essential Clinical History Elements

Document the pattern and migration of pain specifically:

• Periumbilical pain that migrates to the right lower quadrant is highly suggestive of acute appendicitis 2, 3
• Anorexia, nausea, and intermittent vomiting following the onset of pain support the diagnosis 3
• Vomiting before pain onset makes appendicitis less likely 2
• Low-grade fever (typically present but not high-grade) 3

Physical Examination Findings

Perform and document these specific peritoneal signs:

• Right lower quadrant tenderness (most consistent finding) 4
• Rebound tenderness (indicates peritoneal irritation) 4
• Guarding (involuntary muscle rigidity) 4
• Psoas sign (pain with right hip extension or flexion against resistance) - positive sign increases likelihood of appendicitis 2
• Obturator sign (pain with internal rotation of flexed right hip) 2
• Rovsing sign (right lower quadrant pain with left lower quadrant palpation) 1

Critical pitfall: The absence of peritoneal signs does not exclude appendicitis, especially in early presentations, elderly patients, or atypical locations of the appendix 5

Laboratory Testing

Obtain complete blood count with differential and C-reactive protein:

• Elevated WBC count (>10,000/mm³) alone has limited diagnostic value with positive likelihood ratio of only 1.59-2.7 1
• WBC >15,000/mm³ increases positive likelihood ratio to 3.47 1
• C-reactive protein ≥10 mg/L has positive likelihood ratio of 4.24 1
• The combination of WBC >10,000/mm³ AND CRP ≥8 mg/L is most powerful with positive likelihood ratio of 23.32 and negative likelihood ratio of 0.03 1
• Both elevated WBC and left shift together have positive likelihood ratio of 9.8 4

Clinical Scoring Systems

Apply the Alvarado Score for systematic risk stratification:

The Alvarado score (0-10 points) combines: 1

• Symptoms: Migration of pain (1 point), anorexia (1 point), nausea/vomiting (1 point)
• Signs: Right lower quadrant tenderness (2 points), rebound tenderness (1 point), elevated temperature >37.3°C (1 point)
• Laboratory: Leukocytosis >10,000/mm³ (2 points), left shift (1 point)

Interpretation and action based on score: 1

• Scores 1-4: Low probability - consider discharge with close follow-up or observation
• Scores 5-6: Intermediate probability - obtain imaging (CT in adults, ultrasound in children)
• Scores 7-10: High probability - surgical consultation, may proceed to surgery with or without imaging

Important caveat: Low Alvarado scores do NOT reliably exclude appendicitis - studies show 8.4% of patients with appendicitis had scores below 5, and one study found 72% of patients with very low scores (1-4) ultimately had appendicitis 2. Therefore, clinical judgment must override scoring systems when suspicion remains high.

Alternative Scoring System

The AIR (Appendicitis Inflammatory Response) score may be used as an alternative validated tool for risk stratification in adults, even when urinary symptoms predominate 4

Risk Stratification Algorithm

Based on clinical assessment, stratify patients into three management pathways: 1

1. Very low clinical suspicion: Discharge with minimal or no testing, ensure 24-hour follow-up 1

2. Intermediate clinical suspicion:

   • Adults: Obtain CT abdomen/pelvis with IV contrast 1
   • Children: Obtain ultrasound first 1
   • Pregnant patients: Obtain ultrasound first, MRI if inconclusive 1

3. High clinical suspicion: Refer directly to surgeon with minimal or no testing - surgical consultant should be notified as early as clinically warranted 1

Special Populations Requiring Modified Approach

Elderly patients:

• Have higher rates of complicated appendicitis and mortality 2
• CT scan with IV contrast is strongly recommended due to atypical presentations 2
• Lower threshold for imaging even with equivocal clinical findings 2

Children under 5 years:

• Diagnosis is particularly difficult in this age group 6
• Ultrasound is mandatory as first-line imaging to avoid radiation 1
• Higher index of suspicion needed due to communication limitations 6

Women of childbearing age:

• Broader differential diagnosis (gynecologic pathology) 6
• Consider ultrasound first to evaluate ovaries and uterus 7
• Lower threshold for advanced imaging if ultrasound inconclusive 7

Critical Warning Signs

Bradycardia in the presence of fever and abdominal pain is an important alarm signal that may indicate severe peritoneal irritation from vagal response and requires urgent evaluation 5

Common Pitfalls to Avoid

• Do not rely solely on clinical findings without appropriate imaging in intermediate-risk patients - this leads to missed diagnoses 5
• Do not assume normal laboratory values exclude appendicitis - laboratory results are often non-specific 7
• Do not delay surgical consultation in high-risk patients while waiting for imaging 1
• Do not administer analgesics before completing diagnostic evaluation as this may mask peritoneal signs 5
• Repeated clinical examination by experienced clinician remains the cornerstone of diagnosis, particularly when imaging is equivocal 6