My husband has a seizure everytime he takes benadryl is there another kind of allergy medicine that doesn't have diphenhydramine in it?

May not be Benadryl (diphenhydramine) Often the cause of medication side effects is one of the dyes or fillers contained in the medication formula. Check with your pharmacist about a dye free form of Benadryl (diphenhydramine).
Need evaluation. Seizures are a serious side effect of any medication. They could also be something else, like dangerous heart rhythms causing collapse, that needs better evaluation. A thorough history and physical, by your physician, is needed before starting a different type of medication because he may be at risk from other medications besides just the diphenhydramine. Call 911 if he collapses or has seizure.