What are the typical presentations of a patient with appendicitis?

Typical Presentation of Appendicitis

The classic presentation of appendicitis includes vague periumbilical or epigastric pain that migrates to the right lower quadrant (RLQ), accompanied by anorexia, nausea, intermittent vomiting, and low-grade fever—though this complete sequence occurs in only approximately 50% of cases. 1, 2

Core Clinical Features

Pain Characteristics

• Initial pain begins as vague, poorly localized discomfort in the periumbilical or epigastric region 1, 2
• Pain migration to the RLQ is a key discriminating feature and should be specifically assessed 3, 1
• Localized RLQ tenderness is the most consistent finding on examination 3, 2

Associated Symptoms

• Anorexia is nearly universal and often precedes other symptoms 1, 2
• Nausea and vomiting occur but are typically intermittent and non-sustained 1, 2
• Fever is present in only 30-80% of cases, making its absence unreliable for excluding appendicitis 3

Physical Examination Findings

• Peritoneal signs including guarding, rebound tenderness, and muscular defense in the RLQ 3, 1
• Abdominal rigidity may develop as inflammation progresses 2, 4

Age-Specific Variations

Elderly Patients (≥65 years)

The typical triad of migrating RLQ pain, fever, and leukocytosis is infrequently observed together in elderly patients. 3

• Atypical presentations are common, with many elderly patients showing signs of ileus or bowel obstruction 3
• More severe presentations at diagnosis, including abdominal distension, generalized tenderness, palpable mass, and signs of perforation 3
• Delayed presentation is typical, with longer time from symptom onset to hospital admission 3
• Lower diagnostic accuracy with clinical assessment alone compared to younger patients 3

Pediatric Patients (<5 years)

• Atypical symptoms are the rule rather than the exception in young children 1
• Higher perforation rates due to delayed diagnosis from atypical presentation 1

Pregnant Patients

• Presentation may be altered by anatomic displacement of the appendix 4

Laboratory Findings

White Blood Cell Count

• Leukocytosis is common but not universal 3, 2
• In elderly patients, elevated WBC has limited diagnostic accuracy but normal values have high negative predictive value (100%) 3

Inflammatory Markers

• C-reactive protein (CRP) elevation supports diagnosis when combined with other findings 3
• Two or more elevated inflammatory markers increase likelihood of appendicitis 3
• Procalcitonin may help identify complicated appendicitis (AUC 0.94) 3

Critical Diagnostic Pitfalls

Do Not Rely on Single Findings

• Clinical signs and symptoms alone are insufficient for diagnosis, particularly in elderly patients 3
• Laboratory tests alone cannot establish or exclude the diagnosis 3
• Scoring systems (e.g., Alvarado) are useful for risk stratification but should not be the sole basis for diagnosis 3, 1

Common Misdiagnoses

• Approximately 50% of patients present with atypical features, leading to diagnostic challenges 3
• The classic presentation occurs in only about 90% of straightforward cases but far less in complicated populations 2

Diagnostic Approach Algorithm

The strongest discriminators for appendicitis are laboratory tests of inflammatory response combined with clinical descriptors of peritoneal irritation and pain migration. 3

1. Clinical assessment should specifically evaluate for pain migration, RLQ tenderness, peritoneal signs, and anorexia 3, 1, 2
2. Risk stratification using clinical scoring systems (Alvarado, Pediatric Appendicitis Score) to identify low, intermediate, and high-risk patients 1
3. Laboratory evaluation including WBC and CRP to support clinical suspicion 3
4. Imaging confirmation is recommended when diagnosis remains uncertain after clinical and laboratory assessment 3, 1, 5