When you cannot avoid allergens, there are many medicines that can help control allergy symptoms. Decongestants and antihistamines are the most common allergy medications. They help to reduce a stuffy nose, runny nose, sneezing and itching. Other medications work by preventing the release of the chemicals that cause allergic reactions. Corticosteroids are effective in treating inflammation in your nose. An allergist will work with you to determine which medicines are best for you and how often and how much of them you should take—while eliminating or minimizing any side effects.