By Erica Westly

A hundred years after scientists first linked histamine molecules to allergies, the study of histamine pathways is in the midst of a revival, thanks in part to the discovery of a new type of receptor. This fourth known histamine receptor now provides an attractive drug target for seasonal allergies, asthma and possibly even cancer. Erica Westly traces the histamine reaction.

Each autumn, ragweed plants launch their pollen into the air, wreaking havoc on the lives of many millions of ‘hay fever’ victims, who suffer seemingly endless days of watery eyes and sneezing. Doctors initially thought such allergens were poisons, and their guess wasn’t far off. The immune system treats pollen particles as foreign invaders and, in many cases, responds by flooding the body with inflammatory molecules. This overzealous response is triggered by one of the most basic biological messengers, histamine, which has cell receptors in nearly every organ. (Click here to continue reading)

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