Appendicitis

Appendicitis occurs when there's lumen obstruction by a faecolith, foreign body, or fibrosis. Bacteria invade the appendiceal wall, getting trapping, therefore allowing for infection and inflammation to occur.

Differentials - Ectopic pregnancy, UTI, Crohn’s, Mesenteric adenitis, Meckel’s diverticulum

Complications - Abscess, Perforation - presents peritonitic, and is a surgical emergency

Presentation:

Patients present with progressive umbilical pain that localises to the RIF, N+V, and fever.

O/E:

• Tenderness at McBurney’s point (1/3 from ASIS to Umbilicus)

• Rovsing’s sign - Palpation in LIF causes pain in RIF

• Guarding, rigidity, and peritonism if perforation

Any pain that's originating from the visceral peritoneum (covers organ itself) of the abdominal organs causes poorly-localised pain as the organs themselves have fewer nerve endings; patients complain of generalised abdominal pain. In contrast, when this begins to irritate or cause inflammation to the parietal peritoneum (cover inner lining of abdominal wall), the pain becomes well-localised; patients begin to complain of a more specific area of the abdomen that's painful.

• A good example of this is in appendicitis where there's migratory pain from the umbilical region to the right iliac fossa as it progresses. The initial inflammtion stimulates the visceral afferent pain fibres, producing poorly-localised umbilical pain (appendix is a midgut structure). As the appendix becomes more inflamed, it irritates the parietal peritoneum, which activates somatic nerve fibres and produces more localised pain, most often felt in the right iliac fossa.

Investigations:

• Pregnancy test! - rule out ectopic

• Urine dipstick! - rule out UTI

• Bloods - FBC, CRP, VBG (Lactate)

• CT - avoid in children due to radiation (USS good alternative)

• Erect CXR - rule out perforation

Management:

• Appendicectomy

• Prophylactic Abx +/- sepsis 6 if appropriate