Children`s BENADRYL Dye-Free Allergy Liquid Antihistamine Medicine provides kids with effective relief from hay fever and allergy symptoms. Containing 12.5 milligrams of the antihistamine diphenhydramine HCI per teaspoon (5 mL), this liquid allergy medicine relieves runny nose, sneezing, itchy nose, itchy throat, and itchy, watery eyes.