Will benedryl help allergic reaction to peppers?

Depends: Benadryl (diphenhydramine) may help to reduce the runny nose or hives if you have these types of reaction. In anaphylaxis, you must use epinephrine.

If It Is An Allergy: In a true allergic reaction, histamine is released by the body, causing most of the allergic symptoms. An antihistamine, like benedryl, can be pretty effective. If the reaction to the pepper is non-allergic, then benedryl won't help (although it may help you sleep).