Someone Doe Not Have Ongoing Allergies Like Hay Fever, But

someone doe not have ongoing allergies like hay fever, but occasionally after trying something new or is exposed to something they are allergic to, and have a severe allergic reaction, hives, shortness of breath, difficulty swallowing, etcetera. What type of medicine works best to slow down the allergic reaction so you can get to the hospital before going into anaphylactic shock ? I have always been told Diphenhydramine. Is cetirizine, propylhexedrine, or glucocorticoid a better choice, and any of them for occasional use rather than maintenance dose?