Dermatology: Endocannabinoids and Related N-Acylethanolamines in the Skin

The endocannabinoid system—or the broader endocannabinoidome—is an emerging key player in skin homeostasis to the extent that it has recently been termed “c(ut)annabinoid system”. Receptors, mediators, and regulatory molecules are produced/expressed by most skin cellular elements and a plethora of intricate mechanisms are increasingly being acknowledged to explain the endocannabinoidome role in skin homeostasis. Among skin cells, mast cell function is regulated by N-acylethanolamines, among which palmitoylethanolamide (PEA) is the most studied molecule. The purpose of this chapter is to review the body of evidence on the endocannabinoidome’s role in skin physiology and pathology, with particular reference to canine and feline species. The detection of mediators and receptors in the skin will be reviewed. The main dermatological preclinical and clinical data from studies involving animals treated with endocannabinoids and related N-acylethanolamines will also be presented since there is a paucity of clinical evidence utilizing exogenous cannabinoids thus far. Skin allergy represents a promising target for endocannabinoid treatment in the field of veterinary dermatology.