Hives

I have a young daughter (age six) who breaks out sometimes with hives after experiencing an occasional cold. She says it is sometimes itchy when she has hives. The doctors have said that it is all viral and there's nothing that can be done except to give her antihistamines. I don't like the idea of giving her too much antihistamines especially at such a young age and plus antihistamines can be drying to the skin as well. Can you recommend a more natural and non drying remedy/solution or aid. I have changed her diet to incorporate more veggies and fruit, but as a young child she does not always enjoy them. She drinks plenty of water.