Mite allergen induces allergic dermatitis with concomitant neurogenic inflammation in mouse

Pathogenesis of atopic dermatitis involved the interactions of immune and neuroendocrine systems. Here we describe a mouse model for atopic dermatitis with concomitant neurogenic inflammation, by epicutaneous sensitization with a dust mite allergen. Allergen patching resulted in localized dermatitis characterized by pronounced epidermal hyperplasia and spongiosis, which was associated with infiltration of eosinophils and neutrophils, degranulated mast cells, CD4+ and CD8+ T cells, and dendritic cells. There was increased innervation of calcium gene related peptides and substance P in inflamed skins, interactions between nerve fibers and mast cells were seen, indicating the coexistence of neurogenic inflammation. Splenic T cells produced T helper 2-polarized cytokines in response to allergen stimulation in vitro, indicating systemic allergen sensitization. This is the first report of a mouse model of eczema, accompanied by neurogenic inflammation, which shows close resemblance to human allergic diseases. This work supports the notion that the skin is an important site for the initiation of primary allergen sensitization. Besides, this model may also be useful for study of other stress-associated neuroinflammatory skin disorders such as neurogenic pruritus and psoriasis.