Treatment of distal colitis with local anaesthetic agents.

The results of clinical and experimental studies on topical treatment of distal colitis with local anaesthetic agents are summarized. The original observation was an adrenergic hyperinnervation of the inflamed mucosa (hyperinnervation hypothesis). In order to silence local nervous reflexes, the mucosa was treated topically with 2% lidocaine gel. The clinical results are promising and no side effects have been observed. The relapse rate is relatively high and related to the duration of treatment. In studies of experimental colitis a potential antagonism between harmful adrenergic nerves (vasoconstrictor substances and proinflammatory cytokines) and mucosa-protective visceral afferents (antiinflammatory cytokines) in the pathogenesis of colitis is intriguing. Other studies have emphasized the importance of neutrophils for causing damage to the colon epithelium (neutrophil hypothesis) and local anaesthetics have potent effects on several steps of the inflammatory response in addition to the nervous blockade.