Part II: Insect allergies—Inhalation and ingestion: A survey of the literature and our own cases

Background: Allergies to insect stings and bites are common and were partly discussed in part I of this article series. Other mechanisms leading to allergen contact, sensitization, and potential allergy to insects or insects’ compounds can be hard to suspect and diagnose due to their sometimes-hidden character in food or dust. Aims: We aim to provide an overview of allergic reactions to insects elicited by mechanisms other than sting or bite reactions. Sources: A PubMed search on allergy and insects apart from bees and wasps was conducted, articles were selected and included, and a series of relevant publications and cases of our outpatient units are used as examples. Content and implications: Allergies to insects following direct contact, inhalation, and accidental and deliberate ingestion are common and various insect species can elicit these allergies. Sensitization may occur transcutaneously, upon inhalation, and through ingestion. Allergic reactions to edible insects, such as grasshoppers and mealworms, as genuine allergies or as tropomyosin or other protein cross-reactivities in seafood or house dust mite allergic individuals are possible. In Europe, with the licensing of mealworms to be consumed as food and sold commercially in January 2021, allergies and cross-reactivity to insects or insect compounds as foods will become more common and relevant