Epicutaneous application of house dust mite induces allergic skin inflammation and atopic march to the lung upon airway allergen challenge

Atopic dermatitis (AD) in infants is associated with increased risk of developing other allergic diseases, including asthma. This progression is known as atopic march (AM). We established a murine AM model by first inducing AD-like skin inflammation to house dust mite (HDM) allergen. Mice were subsequently challenged with HDM delivered to the lung. Our data show that epicutaneous sensitization with HDM increased serum IgE, ear thickness, and immune cell infiltration into the skin, accompanied by an increase in CD4⁺ tissue-resident memory T cells (Trm) in the lung. Following pulmonary HDM challenge, eosinophil influx and T2 inflammation were increased in the lung. Together, our data suggest communication between the skin and lung, where allergen sensitization on the skin increases lung Trm and amplifies the T2 allergic response to lung allergen challenge. This clinically relevant model could help identify novel targets for local interventions to reduce the progression of AD to asthma.