Antihistamines Say: an-tuh-his-tuh-meenz Antihistamines are medicines that block allergy symptoms. They can make you stop sneezing, and stop your nose from running when your allergies are acting up. When you are itchy or have hives, they can work, too. Back to Articles Related Articles Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.