Perhaps you or someone you know experiences that sneezing and watery eye response from common allergies to pet dander, pollen and air carried molds or even venom from an insect enters your body. Our immune response is to release antibodies (which are special proteins) that fight back by reacting with the offending irritant (called an allergen.) Then our bodies need to get rid of the tied-up allergen. This is where histamine triggers reactions that help clean up the battlefield of antibodies and allergens. Lets explore the molecule-based connections between allergens, antibodies and especially histamine. These three substances interact in some interesting ways that provide the molecular explanation for those allergic 30 miles per hour sneezing outbursts.