Acute appendicitis and chronic appendicitis are quite different. Acute appendicitis develops suddenly with clear symptoms of fever and vomiting, and the pain in the lower right abdomen is relatively severe. Chronic appendicitis, on the other hand, often develops as a result of prolonged acute appendicitis. The abdominal pain is not typically characteristic, generally with few instances of fever or vomiting, but it can include persistent abdominal pain. Chronic appendicitis can lead to the formation of an abscess around the appendix, and a lump can be felt in the lower right abdomen. Acute appendicitis generally requires prompt surgical treatment to prevent its transition into chronic appendicitis.