Which of the following is a common feature of early appendicitis?

In early appendicitis, neutrophilia is indeed a common feature. This condition arises as a response to inflammation, which is a hallmark of appendicitis. When the appendix becomes inflamed, the body initiates an immune response, leading to an increase in white blood cells, particularly neutrophils, which are crucial in fighting off infection. This shift in the white blood cell count is a key component of the diagnostic criteria for appendicitis and supports the inflammatory nature of the condition.

In the context of the other options, muscle rigidity may occur in the later stages of the illness or if there is significant irritation of the peritoneum, but it is not as typical in the early stages. Severe abdominal pain is also a characteristic of appendicitis; however, during the very early stages, the pain may not reach severe levels. A high fever, particularly above 39°C, generally indicates a more advanced or systemic infection and is not typically present in the early phase of appendicitis, where mild fever or no fever may be observed instead. Thus, the rise in neutrophil count is a more reliable indicator of the early inflammatory process occurring in appendicitis.