Help please! is epipen (epinephrine) jr auto injectors used for all allergic reactions or just emergency reactions?

Limited use: The value of an Epipen (epinephrine) is its ability to help block a tragic evolving allergic reaction and provide time for a person to reach urgent followup care.It's effect is relatively short (hour or so).If you simply break out in hives as a food reaction, it could help some, but since the food will be processed in your body for days, a longer agent like Diphenhydramine or citirazine would be more benificial.