Acute right lower quadrant pain with nausea, vomiting, and a high white blood cell count is most likely which condition?

• A. Appendicitis
• B. Cholecystitis
• C. Pancreatitis
• D. Diverticulitis

Answer: (A)

The scenario is testing recognition of acute appendicitis. Inflammation of the appendix classically presents with pain that starts around the umbilicus and then localizes to the right lower quadrant, accompanied by nausea or vomiting and a leukocytosis. The leukocytosis reflects the inflammatory response, often with neutrophilia, and can accompany fever as the process progresses. The localizing pain in the RLQ, along with systemic signs, points to irritation of the peritoneum in that area from an inflamed appendix.

Cholecystitis would more typically cause right upper quadrant pain with symptoms related to meals and a positive Murphy sign, not the exact RLQ location. Pancreatitis usually presents with epigastric pain radiating to the back and common risk factors like alcohol use or gallstones, not isolated RLQ pain with leukocytosis. Diverticulitis tends to cause left lower quadrant pain, sometimes with fever and leukocytosis, which does not fit the right-sided location here.

Imaging choices, such as ultrasound or CT, are used to confirm appendicitis, especially when the clinical presentation is not crystal clear. Labs often show leukocytosis, supporting an inflammatory process, and further imaging helps prevent perforation from delays in treatment.