How much can a 170lb man take for allergic reaction; hives, swelling, possible trouble swallowing?

If you have trouble. swallowing you may have something called angioedema, which is reactionary swelling of the mucosal surfaces and blood vessels, which can be serious enough to obstruct your breathing from throat swelling. Please proceed to the emergency room to be evaluated. Benadryl (diphenhydramine) taken at 25 or 50 mg oral doses may alleviate some swelling and itching.