Brother has been complaining about being itchy and has red spots/bumps all over. He was told it was allergies. Now a month later I'm starting to get it?

Not all hives.. .. are allergies. A common cause of acute hives is a subclinical (otherwise asymptomatic) viral infection. Another possible explanation for sudden hive onset in 2 individuals is irritant exposure (eg new laundry detergent). A third is an insect exposure such as fleas or bed bugs. Hives for over a month should be discussed with an Allergist to help identify triggers and an effective treatment.