Tom:
What you're describing are urticaria, or hives. 99% of the time, hives are not allergic, but instead come for no reason. They come and go, changing from hour to hour. Hives appear as red, itchy bumps. They may disappear for long periods, only to recur another time, often much later.
People always try to correlate hives with something. Favorites are: food, soap, detergent, fabric softener, viruses, and stress. These correlations rarely stand up.
My advice to hive-sufferers is:
1. Don't make yourself crazy looking for allergies.
2. Don't do blood tests.
3. Apply an OTC itch lotion as needed (Sarna is good.)
4. Take an OTC antihistamine if needed 1-3 times a day, such as diphenhydramine or chlorpheniramine.
5. Relax--hives generally go away as mysteriously as they came. And they aren't contagious.
Good luck.
Dr. R
I too suffer from hives that seem to come and go. I have heard that they can also be stress related. Whatever the reason, they are irritating and very itchy!!! Best of luck to you.