My Husband Was Stung By A Wasp Today On The

My husband was stung by a wasp today on the top of his hand and the hand is quite swollen and hurts badly. He is not allergic, has been stung in the past, but has not had this much swelling. He has no fever or other symptoms of concern. We are icing the hand 20 minutes per hour, have put Benadryl on the wound site and have dapped vinegar on a cotton ball. Any other recommendations?