Like few other peripheral organs in the mammalian system, the hair follicle has turned out in recent years to be an unconventional and still very incomplemetely characterized, but important target tissue for multiple neurohormones, neuropeptides, neurotransmitters, and neurotrophins. It has become ever-clearer that these neuro-mediators profoundly impact on hair follicle development, growth, cycling and pigmentation. Yet, disappointingly few investigators have been attracted to this field, which many still consider an ivory tower habitat. However, evidence that e.g. hair follicle melanocytes, melanocyte stem cells and epithelial stem cells all underlie important neuroendocrine controls, and the increasing recognition that even human scalp hair follicles differentially express a stunning array of these neuro-mediators are slowly changing this view.

Here, the author's personal journey through the skin neuroendocrinology galaxy is sketched so as to provide some - very subjective and utterly biased - guidance on which specific lessons from hair follicle neuroendocrinology are biologically most fascinating, and may currently be most promising in terms of future clinical applications in and beyond dermatology. Focusing on ievidence that equivalent systems of the hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-thyroid (HPT) axes exist in normal human skin and hair follicles, selected surprises and open questions are discussed that have emanated from the author's meanderings through this research jungle. This "hitchiker's guide" concludes with a list of five specific open questions, which the author feels deserve to be explored and answered with highest priority.