From the Guidelines
Leukocytosis is present in approximately 50% of patients with appendicitis, as indicated by recent guidelines 1.
Amount of Leukocytosis in Appendicitis
The amount of leukocytosis in appendicitis can vary, but it is generally characterized by a moderate elevation in white blood cell count.
- The white blood cell count can range from 10,000 to 18,000 cells per microliter of blood, with some cases exceeding 20,000 cells/μL, especially in cases with perforation or abscess formation.
- A left shift, which is an increased percentage of neutrophils, often above 75%, frequently accompanies the leukocytosis.
- It's essential to note that some patients, particularly elderly individuals or those who are immunocompromised, may not develop significant leukocytosis despite having appendicitis.
Diagnostic Considerations
While leukocytosis supports the diagnosis of appendicitis when combined with clinical symptoms and other findings, it is not specific to appendicitis and can occur in many inflammatory or infectious conditions.
- The use of clinical scores, such as the AIR score and AAS score, can help identify patients with suspected acute appendicitis and decrease the need for imaging studies and hospital admissions 1.
- Laboratory tests, including white blood cell count and serum inflammatory biomarkers, can be useful in predicting acute appendicitis, especially in pediatric patients 1.
Recommendation
In patients with suspected appendicitis, a tailored individualized diagnostic approach is recommended, taking into account disease probability, sex, and age of the patient, as well as laboratory tests and imaging studies as needed 1.
From the Research
Leukocytosis in Appendicitis
- The amount of leukocytosis in appendicitis is a topic of interest in medical research, with various studies investigating its diagnostic value 2, 3, 4, 5, 6.
- A study published in 2004 found that an elevated total white blood cell (WBC) count had a sensitivity of 76% and a specificity of 52% for diagnosing appendicitis, but its clinical utility was limited due to poor sensitivity and specificity 4.
- Another study from 1998 found that a normal WBC count was seen in 11% of patients with pathologically confirmed appendicitis, and there was no difference in age, temperature, gender, or severity of disease between patients with normal and elevated WBC counts 5.
- A 2018 study recommended surgical treatment for patients suspected of appendicitis with an appendiceal diameter of ≥8 mm, even if their WBC count and neutrophil count were normal 6.
- The diagnostic accuracy of WBC count and C-reactive protein (CRP) levels in relation to symptom duration was evaluated in a 2015 study, which found that no value of WBC count or CRP level could safely and sufficiently confirm or exclude the diagnosis of acute appendicitis in patients with abdominal pain of 5 days or less in duration 3.
Diagnostic Value of Leukocytosis
- The studies suggest that leukocytosis is not a reliable indicator of appendicitis, and its diagnostic value is limited 4, 5.
- A combination of clinical, imaging, and laboratory findings is necessary for an accurate diagnosis of appendicitis 2, 6.
- The presence of appendicoliths, mass effect, and a dilated appendix greater than 13 mm on computed tomography (CT) scans are associated with a higher risk of treatment failure with an antibiotics-first approach 2.