IGHE and Erythema: The frequency of treatment-related adverse events was low: 3 (6.5%) and 6 (13%) participants in the intradermal immunotherapy and control groups, respectively, experienced mild systematic reactions manifested as generalized pruritus only, except for 1 participant receiving intradermal allergen who had erythema tracking from the injection site in a lymphatic distribution (IgE-mediated lymphangitis) 20 minutes after each injection.