n. inflammation of the vermiform appendix. Acute appendicitis, which became common in the 20th century, usually affects young people. The chief symptom is abdominal pain, first central and later (with tenderness) in the right lower abdomen, over the appendix (see McBurney’s point). Unusual positions of the appendix may cause pain in different sites, leading to difficulty in diagnosis. Vomiting and diarrhoea sometimes occur, but fever is slight. If not treated by surgical removal (appendicectomy) the condition usually progresses to cause an abscess or generalized peritonitis. Conditions that mimic appendicitis include mesenteric lymphadenitis, terminal ileitis (see Crohn’s disease), right-sided ectopic pregnancy, a right-sided kidney stone, pyelonephritis, and (rarely) right-sided pneumonia. Chronic appendicitis was a term used 20–50 years ago to explain recurrent pains in the lower abdomen; it is no longer used.
Subjects: Medicine and Health.