Increased expression of β2‐adrenoceptors is involved in vitiligo‐associated grey hair

To the Editor, Melanin is a hair pigment produced by active follicular melanocytes above the hair papilla. Melanocytes (MCs) are generated during downward migration and differentiation of inactive melanocyte stem cells (MelSCs) and melanocyte progenitor cells (MelPCs). It has been demonstrated that the sympathetic nerves activate the mechanism of acute stress-induced grey hair and lead to a sudden release of the neurotransmitter norepinephrine. This promotes the rapid proliferation, differentiation and migration of MelSCs, resulting in permanent depletion of MelSCs.