What is the diagnosis based on a Complete Blood Count (CBC) With Differential/Platelet showing leukocytosis and elevated C-Reactive Protein (CRP)?

Interpretation of CBC and CRP Laboratory Results

The laboratory results indicate an acute inflammatory condition, most likely an infection, characterized by leukocytosis with neutrophilia and elevated C-reactive protein. 1

Analysis of Laboratory Values

Complete Blood Count (CBC) Findings:

• Leukocytosis: WBC count of 13.6 K/uL is elevated above normal range, indicating an inflammatory response 1
• Neutrophilia: Neutrophil percentage of 75.0% shows a predominance of neutrophils, suggesting an acute inflammatory process 1
• Monocytosis: Monocyte percentage of 10.7% is elevated, often seen in inflammatory conditions 1
• Lymphopenia: Lymphocyte percentage of 12.7% is relatively low, which can occur during acute stress or infection 1
• Thrombocytosis: Platelet count of 421 K/cumm is elevated, commonly seen in inflammatory states 1
• Normal hemoglobin and RBC parameters: Hemoglobin (15.6 gm/dL) and RBC count (4.99 M/mm3) are within normal limits 1

Inflammatory Marker:

• Elevated C-reactive protein: CRP of 0.44 mg/dL is elevated, confirming an active inflammatory process 1

Clinical Significance

Diagnostic Implications:

• The combination of leukocytosis with neutrophil predominance and elevated CRP strongly suggests an acute inflammatory condition, most likely infectious in nature 1, 2
• This pattern is commonly seen in bacterial infections rather than viral infections 3
• The moderate elevation of WBC count (13.6 K/uL) with neutrophilia (75%) is consistent with an acute bacterial infection in its early stages 1

Differential Diagnosis:

• Bacterial infection: The most likely cause given the laboratory profile 1, 2
• Acute inflammatory bowel disease flare: These lab findings are consistent with IBD activity 1
• Early appendicitis: Characterized by similar laboratory findings of leukocytosis and elevated CRP 2, 4
• Soft tissue infection: Consistent with early cellulitis or other soft tissue infections 1
• Acute diverticulitis: Often presents with this laboratory profile 1

Clinical Correlation Required:

• These laboratory findings should be correlated with clinical symptoms such as fever, localized pain, or other signs of infection 1
• The degree of elevation is moderate, suggesting an acute but not necessarily severe infection 5
• If symptoms include abdominal pain, consider acute appendicitis or diverticulitis 1, 2
• If symptoms include joint pain or rash, consider inflammatory conditions like Adult-onset Still's disease 1

Recommendations

• Further clinical assessment is needed to determine the source of inflammation based on patient symptoms 1
• Consider blood cultures if fever is present, especially if temperature exceeds 38°C 1
• Additional laboratory tests may be warranted depending on clinical presentation, including:
  • Urinalysis if urinary symptoms are present 1
  • Stool cultures if gastrointestinal symptoms are present 1
  • Imaging studies based on localized symptoms 1
• Monitor trends in these laboratory values to assess response to treatment 5
• Empiric antibiotic therapy may be appropriate if bacterial infection is strongly suspected based on clinical presentation 1

Interpretation Pitfalls

• Leukocytosis can be caused by stress or corticosteroid use, not just infection 6
• CRP elevation, while sensitive for inflammation, is not specific for the type of inflammatory process 5
• Normal values in elderly or immunocompromised patients may not rule out significant infection 1
• The combination of elevated WBC, neutrophilia, and CRP has higher specificity for bacterial infection than any single test alone 2, 4