A number of clinical and laboratory based scoring systems have been devised to assist diagnosis. The most widely used is Alvarado score.
- Migratory right iliac fossa pain 1 point
- Anorexia 1 point
- Nausea and vomiting 1 point
- Right iliac fossa tenderness 2 points
- Rebound tenderness 1 point
- Fever 1 point
- Leucocytosis 2 points
- Shift to left (segmented neutrophils) 1 point
Total score 10 points
A score below 5 is strongly against a diagnosis of appendicitis, while a score of 7 or more is strongly predictive of acute appendicitis. In patients with an equivocal score of 5-6, CT scan is used in the USA to further reduce the rate of negative appendicectomy.