IGHE and granular corneal dystrophy type II: Pivotal evidence of neuroimmune inflammation and MC contribution is the increased number of MCs in skin lesions from patients with ACD and, on the other side, the higher expression of pro-adrenomedullin peptide 12 (PAMP12), a ligand of MRGPRX2, compared to healthy subjects: experiments on MrgprB2MUT mice highlighted differences in scratching, itch behavior, and immune cell recruitment, suggesting the involvement of IgE/FcεRI-independent pruritogenic pathways [72].