Prominent vomiting is unusual and suggests the possibility of another diagnosis, such as gastroenteritis or small bowel obstruction. Fever is usually low grade. High fever or rigors suggest perforation. Local hyperesthesia of the skin in the right lower quadrant may be noted. With worsening of the inflammatory process, voluntary guarding progresses to involuntary muscle rigidity.
Free perforation leads to generalized abdominal tenderness and rigidity.
An abdominal mass suggests phlegmon or abscess formation. If the diagnosis is not clear at presentation, repeat of the physical examination within a few hours may clarify matters. There are no laboratory studies specific for appendicitis. Urinalysis may show a few white blood cells or red blood cells. Atypical location of the appendix leads to atypical clinical presentations.