Cutaneous innervation and the role of neuronal peptides in cutaneous inflammation: a minireview.

Noxious stimuli may directly activate peripheral nerve endings of primary sensory neurons. Such impulses are conveyed centrally as well as, through antidromic axon-reflexes, peripherally where they release pro-inflammatory neuropeptides that cause the set of changes collectively referred to as "neurogenic inflammation". These peptides are able to regulate cutaneous inflammatory processes. Thus, for instance, quantitative variations in cutaneous levels of some neuropeptides, such as calcitonin gene-related peptide, neuropeptide Y, substance P, vasoactive intestinal polypeptide, neurokinin A and somatostatin, have been found in lesional skin in a number of dermatoses. In addition, they may also serve as selective markers of nerve fiber degeneration and regeneration, and they can also act as trophic agents.