Bless you, allergy sufferers. That sneezing-wheezing-coughing-itching, hard-to-focus-on-anything time of year is back with a vengeance. Symptoms associated with allergies are annoying for most. But for others, allergic reactions may lead to more serious conditions such as asthma and sinus infections. If left untreated, a patient’s quality of life may suffer. An estimated 26 million Americans — roughly 20 percent of the population — are affected by seasonal allergies, according to the American Academy of Allergy, Asthma and Immunology.