Within 12 to 24 hours, inflammation usually becomes transmural, involving the adjacent parietal peritoneum. At this time, patients may note exacerbation of pain by coughing, sneezing, or movement. Unfortunately, this classic sequential presentation does not occur in all patients. Some may present initially with right lower quadrant pain. 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.