I am severely allergic to shellfish. i was prescribed an epipen (epinephrine). i never had to use one yet. how do you know if you need to use it? does it reverse?

Breathing /fainting: If you develop breathing, fainting, gastrointestinal symptoms especially when associated with hives, itching, or flushing, use the epipen immediately, Repeat in 5 minutes if necessary. Recent findings showed that using the epinephrine

You will know: Keep your Epi pen with you at all times. Make sure it is up to date. General symptom-those that got you the prescription in the first place but especially throat swelling or trouble breathing. Once you use it it is best to dial 911. Benadryl (diphenhydramine) may also help if taken while you can swallow. The Epi effects wear off over time, though they may be uncomfortable this medicine is life saving