What would cause hives every evening around the same time?

United States
@shizuoka (352)
April 20, 2008 10:40pm CST
About two weeks ago my husband started getting hives around 5 or 6 in the evening. At first he thought it was the new brand of shower soap we had, so he asked me to buy his usual brand. He was getting puffy, itchy bumps all over his body (like big spider bites). We changed soap but he still gets them. He eats different foods every day, but gets the hives around the same time, regardless. I thought maybe it was something in the house that caused him to have hives when he arrived home from work, but it even happens on the weekend. They show up in the evening. This evening he got them on his face. All around his mouth and chin it was swollen and puffy. He's been taking Benedryl, which helps, but we're puzzled. Has anyone out there ever heard of something like this?