At this point it doesn’t seem as if cholinergic urticaria is contagious in any way. My wife doesn’t have it after all the years we have been together, and no one in my family has ever had it. It may be inherited (or genetically carried), but at this point it doesn’t seem as if it is contagious.
However, I wonder if someone received a transplant of our blood, plasma, or bone marrow if they would eventually also develop chronic cholinergic urticaria (heat hives). I have never donated any blood, plasma, organs, or bone marrow, but it is an interesting question.
After all, we still don’t know exactly what causes CU to develop in the first place. Bacteria and viruses can certainly be transmitted. Antibodies may be able to be transferred (I am not sure about the autoimmune disorders). I did look at one website (the red cross) about blood donation, and it seemed to indicate that if you had allergies there was no issues with donating blood. Something that surprised me is that they even allow you to donate blood if you have had CANCER (as long as it wasn’t a blood related cancer). That surprised me.
But it does definitely seems as if the potential is there that it is possible that in some way the person that received our donated material could develop CU. I wouldn’t want to give this condition to my worse enemy, much less a poor person needing a donation of blood. But then again, I suppose if it were a life or death situation it may not be that bad giving others hives (potentially), and they may prefer itching to death.
But at the same time, I think I will avoid donating any blood, plasma, bone marrow, or anything else just in case. Better to be safe than sorry–at least until we can find more out about this condition. For all I know my blood is like a toxic acid…just kidding.