Poison Ivy on my boyfriend's junk

Me and my boyfriend went camping. On the way back he had to pee so he went peeing in this bush plant thing. When I saw him peeing I remember thinking in my head "Is that poison ivy?" But since I think I'm an idiot and have no faith in my knowledge I just assumed I was wrong. Well turns out I was right. We are home now and he had a full flown poison ivy rash on his junk and legs. We are going to urgent care in the morning. Does anyone have any home remedies for poison ivy in the mean time because he is miserable.