Which combination of tests is confirmatory of appendicitis in a patient with RLQ pain?

The combination of abdominal ultrasound and a white blood cell count (WBC) of 10-20 is confirmatory of appendicitis in a patient presenting with right lower quadrant (RLQ) pain. Appendicitis typically presents with RLQ pain, nausea, and fever, and a differential of appendicitis is often explored through imaging and laboratory tests.

An abdominal ultrasound is particularly useful in diagnosing appendicitis, especially in children and pregnant women, as it avoids ionizing radiation. The presence of an inflamed appendix or fluid collection in the RLQ on ultrasound can strongly suggest appendicitis.

Additionally, an elevated white blood cell count is consistent with an inflammatory process such as appendicitis. A WBC count of 10-20 indicates leukocytosis, which often accompanies infections, including appendicitis.

In summary, this combination effectively corroborates the diagnosis of appendicitis by providing both imaging evidence and laboratory support for inflammation.