HRH4 and skin disorder: In light of the results obtained in this work, we believe that future experiments should consider the combined use of H3R and/H4R antagonists, which would be beneficial in reducing the symptoms associated with dermatitis, as blocking the H3R would decrease the scratching action, which is an initial event in these pathologies, inducing damage to the epithelium that triggers the initial inflammatory response, and blocking H4R would induce a tolerant microenvironment by interacting with tissue DCs.