Compare to the active ingredient in Children's Benadryl Allergy Liquid. Soothe your child's allergy symptoms with Children's Allergy Relief. This complete allergy medicine for kids provides 4-6 hours of multi-symptom relief for sneezing, runny nose, itchy throat or nose and itchy, watery eyes. The active ingredient is Diphenhydramine HCl, a powerful antihistamine that relieves symptoms of hay fever or other upper respiratory allergies. Just one dose of this cherry-flavored liquid provides multi-symptom relief from indoor and outdoor allergies. This allergy medication is for children ages 6-11 years. Dosage cup is included. Take every four to six hours, or as directed by a doctor. Gluten and alcohol free.