IL21 and Allergy: •Microneedles reduced allergy symptom score and serum mmcp1 levels•Microneedles prevented allergen-induced hypothermia•Microneedles decreased antigen-specific IL-4, IL-5 and IL-21 in the spleen and MLN•Microneedles increased antigen-specific IFNγ in the spleen and MLN•Microneedles increased antigen-specific IL-10 in the MLN. Microneedles enhance serum IgG2a and IgG2b and decrease serum IgE compared to EPIT