It is spring, the time of year when April showers bring May flowers, and children hunt for Easter eggs on manicured green lawns; or at least I've read about these things in books. For those of us living above the 40th parallel, it is the season sump pumps become overwhelmed by run-off, gravely snow piles keep their strong hold on north facing slopes, and you look around your yard wondering how one dog made all that mess. I would like to add, to the list of springs' rites of passage, the start of the outdoor allergy season. It begins every year in late April. The add-on slots in clinic quickly fill with stuffed up patients exclaiming "Sinus infection!", or worse, those with red, watery eyes who have been ostracized by coworkers for fear of the dreaded "pink eye," (though actual bacterial conjunctivitis is exceedingly rare). Often a quick review of these patients' charts show they have the same set of symptoms every April, helping to identify the real culprit: environmental allergies.