The neuroendocrine-immune connection regulates chronic inflammatory disease in allergy.

Allergy is an instructive model to study neuroendocrine-immune interaction in chronic inflammation, a key research task taken on by a relatively new scientific field: psychoneuroimmunology (PNI). Itch, as the prime symptom of many chronic inflammatory diseases but especially of allergic inflammation, hints at the prominent role of neurogenic inflammation in the course of the disease. Environmental factors ranging from allergens to perceived stress can trigger the release of neuropeptides from peripheral nerve endings that than activate mast cells and induce an exaggerated alarm response in peripheral organs such as the skin. Beyond this innate immune response, neuroendocrine-immune interaction regulates specific immune balance. Depending on intensity and timing of neuroendocrine activation, especially neuropeptides and neurotrophins either enhance or suppress tissue regeneration and inflammation, the conditions of which will be discussed in detail here. Allergic inflammation thus serves to understand the clinical and therapeutic implications of neuroendocrine-immune interaction in chronic inflammatory disease and its implications for future treatment strategies.