Why does the pain of appendicitis move from the periumbilical area to the RIF?
Remember that the appendix is innervated by the autonomic nervous supply to the mid-gut. Inflammation in the appendix activates afferent sympathetic fibres, which enter the spinal cord at T10 resulting in referred colicky pain to the periumbilical area [3]. Eventually inflammation in the appendix will irritate the surrounding parietal peritoneum, which is innervated by the intercostal nerves resulting in constant local pain in the RIF.
Remember that visceral pain is normally vague, colicky and felt in the midline.
Somatic pain is more constant, and felt at the local site [3,5].
Learning bite
The classic migrating of pain of appendicitis has a sensitivity and specificity of around 80% [3,5].