Besides the involvement in immediate-type allergy and maturation of dendritic cells, histamine also stimulates human keratinocytes through the H1 receptor to increase the expression of the proinflammatory cytokine IL-6, the chemokine IL-8 [5], the nerve growth factor (NGF) [6], and matrix metalloproteinases (MMPs), especially MMP-1 and MMP-9 [7, 8]. Here, NGF is linked to allergic disease.