My Husband Broke Out In Hives. I Now Have Them

My husband broke out in hives. I now have them and so does my daughter who does not live with us and my son who does not live with us. They are like a measle and are very itchy. So much so that I can't sleep. Went to the dermatologist and he put my husband on a steroid pill and gave him a med that when applied helps the itch some. It seems to be worse when the area gets warm like on the back legs upper arms anyplace where there is clothing. My daughter has had this since February and my husband 2 months me just a month and my son a few weeks. Any ideas would be appreciated thanks.