Tag: cross-reactivity antihistamines

Antihistamine Allergies and Cross-Reactivity: What to Watch For

Antihistamine Allergies and Cross-Reactivity: What to Watch For

Some people develop hives or worsened allergies from antihistamines instead of relief. This rare but real reaction involves paradoxical activation of H1 receptors. Learn the signs, what drugs to avoid, and how to find safer treatments.