Does a history of chickenpox mean immunity?

Yes, if dx correct: Having chicken pox confers immunity, yes. The problem is that other rashes resemble chicken pox. Was the diagnosis was made by a dermatologist or pediatrician, or by somebody's aunt sadie? If it's important to know for sure, your doctor can order a varicella titer, which will tell you if you have antibodies to the virus in your blood.

Usually: A verified history of natural chickenpox is usually accepted as indicative of long term immunity. In some cases those kids who had spots but never saw the doc may have had something else.There is a blood thest that can confirm past chickenpox.