I have suffered from allergies most of my life. Since taking allergy shots, they aren't quite as bad, but there can be times when my allergies flare up and I have to have some quick relief. I have tried multiple allergy products, but one of the best I've found is that of Tylenol Severe Allergy. The regular dosage is 2 pills, however if I have to take them during the day, I have found I can only take 1 at a time, as they do tend to make you drowsy.
These pills do however, do a good job of relieving my allergy symptoms. They don't completely go away, but they are definitely less noticeable and less of an irritant after I have taken this medication. It is also good if you have a headache or other ache as it does have some pain reliever in it.