If you find yourself struggling to come up with a particular incident involving allergies, dig out your interviewing hat! Consider interviewing a friend or family member about their own instances of allergic reactions. First, check out this article from The Next Scoop: “How to Write Interview Questions to Get a Good Story.”
Alternatively, if you don’t have allergies in the true sense of the word, write about some character traits that you might be allergic to. Narcissism? Vanity? Noisy chewing? Whatever trait you select, write about an incident that really got under your skin.