This is an inﬂammatory condition of the APPENDIX, and is a common surgical emergency, aﬀecting mainly adolescents and young adults. It is usually due to a combination of obstruction and infection of the appendix, and has a variable clinical course ranging from episodes of mild self-limiting abdominal pain to life-threatening illness. Abdominal pain beginning in the centre of the abdomen but which later shifts position to the right iliac fossa is the classic symptom. The patient usually has accompanying fever and sometimes nausea, vomiting, loss of appetite, diarrhoea, or even constipation. The precise symptoms vary with the exact location of the appendix within the abdomen. In some individuals the appendix may ‘grumble’ with repeated mild attacks which resolve spontaneously. In an acute attack, the inﬂammatory process begins ﬁrst in the wall of the appendix but, if the disease progresses, the appendix can become secondarily infected and pus may form within it. The blood supply may become compromised and the wall become gangrenous. Eventually the appendix may rupture, giving rise to a localised abscess in the abdomen or, more rarely, free pus within the abdomen which causes generalised PERITONITIS. Rupture of the appendix is a serious complication and the patient may be severely unwell. Surgeons recognise that in order to make sure patients with appendicitis do not progress to peritonitis, a certain percentage of normal appendixes are removed when clinical signs are suspicious but not diagnostic of disease.
Treatment The best treatment is prompt surgical removal of the diseased appendix, usually with antibiotic cover. If performed early, before rupture occurs, APPENDICECTOMY is normally straightforward and recovery swift. If the appendix has already ruptured and there is abscess formation or free intra-abdominal pus, surgery is still the best treatment but postoperative complications are more likely, and full recovery may be slower.