I wouldn't bring an epipen as a just in case thing - in case a youngun experienced suddent unexpected anaphylaxis. A child is seizing on the ground, her throat is closing up - she isn't known to be allergic, do you really know what's going on, enough to justify the epipen injection? Without any history of allergic reactions, I'd do my best to interrupt the presumed histamine / antihistamine roller coaster with benadryl, and get medical assistance pronto.