What follows is an excerpt from a post on earthclinic. I hope it helps.
Lysine: "I think she would take 2 in the morning and 2 at night. They started going away immediately and she's even off the L-lysine now and hasn't had a recurrance in over two years! She had my grandfather use it and it worked for him too." (posting on earthclinic.com)
Note: Lysine is cheaper and easier to take if you buy the powder and just take a spoonfull of it. No taste, easier than taking tablets. Lysine is a very safe amino acid with strong anti-viral properties.
My son (then 7 years old) developed excercised induced uticaria, (hives). What works for him is a cool shower immediately, as soon as possible when the hives appear.
My son developed hives for the first time when he was given Amantadine, (an anti-viral drug). Now anytime he is overheated or sweaty, he has hives.
I think the amantadine upset some type of viral balance in his gut. This would explain why some hives respond to vinegar and baking soda, and garlic, (all mild antivirals). It would also explain why in a previous post one twin had hives and the other does not, (it is not hereditary) but it can be found in families, (as viri can be transmitted).
Hope this helps someone. I will be starting my son on the lysine. Summer will be miserable for him if I don't do something.