Abstract Cutaneous mast cells underly numerous skin inflammatory processes. Our study reveals that the ablation of a subset of sensory nonpeptidergic neurons expressing MrgprD increases the expression of a mast cell gene module, including the activating receptor, Mrgprb2, leading to increased mast cell reactivity to MrgprB2 ligands, and cutaneous inflammation in several disease models, such as irritant dermatitis and rosacea. MrgprD-expressing neurons releases glutamate to inhibit mast cell responsiveness. Reducing glutamate release from MrgprD-expressing neurons in the periphery resulted in a hyperresponsive state of mast cells. The antagonism of glutamate receptors on cultured peritoneal cavity mast cells (PCMCs) enhances MC degranulation and phenocopied the genetic state in the absence of MrgprD-expressing neurons. We subsequently identifies the kainate receptor GluR6/KA2 as the glutamate receptor subtype expressed on dermal MCs. Two non-specific agonists of GluR6, and the highly selective GluR6 agonist SYM2081 suppress the degranulation of PCMC in response to MrgprB2 activation but not FcɛRI crosslinking in a dose-dependent manner. In vivo, intradermal delivery of SYM2081 suppresses compound 48/80 induced-dermal MC activation, and attenuates croton oil-induced irritant dermatitis, but not IgE-dependent passive cutaneous anaphylaxis. Together, these data demonstrate that glutamate acting via the GluR6/KA2 receptor promotes mast cell hypo-responsiveness during homeostasis and suggests that selective agonism of this pathway has the potential to reduce mast cell activation in vivo, which would be of significant utility in the treatment of diseases where mast cells represent a key component of the pathogenic pathway.