hi perhaps you are allergic to something associated with sex e. g. condoms lubrication gels vaginal juices perfumes etc. or possibly something you consume before sex. keep a journal of everything associated with sex and the hives and perhaps you will find the culprit. try using latex free condoms that could really be a big part of your penis problem. as for hives that could just be down to you as this is totally natural. in desmond morris's book "the naked ape" meaning us he has a whole chapter on the "sex hives" or rash that some people get across their chest shoulders belly or back. hope this helps you. good luck
after sex tip of penis gets red-ish in color and hives appear around the belly button region. what could it be? . has occurred after past 3 sexual experiences. vaginal intercourse only occurred twice of three occurrences. oral during all. red-ness on penis tip lasts typical less than 24-48 hours then disappears for good same with hives. not tender to touch and doesn't hurt. hives make me feel some sort of allergy but still unsure as to what or if it has potential to be an sti.