When your allergies flare up, it's easy to reach for something over the counter; but beware, some of these common products can have pitfalls.

"As a general rule we try to avoid topical decongestants, whether it's for the eyes or for the nose," says Dr. David Stukus, an allergist at Children's Hospital.

That's how medicines like Neo-synephrine, Afrin and redness relievers work. The problem is rebound. They work, but for shorter intervals, and when the symptoms return, they are worse than ever before. "I've had several patients in that situation," Dr. Stukus said. "People become physically addicted to these medications."

Decongestants that you take by mouth can also cause rebound and they can affect your whole body - an increase in blood pressure, jitteriness, insomnia. "I see this frequently in young children, who take these medications actually, and this is why they are no longer recommended for treatment in young children," says Dr. Stukus.

With combo medications, you're probably taking stuff you don't need. "There's only one medicine in there that is an actual allergy medicine and that would be the antihistamine," says Dr. Stukus. But antihistamines, especially older ones, can cause drowsiness.

The acetaminophen doesn't help allergies, and the decongestant can cause rebound. Newer, over-the-counter drugs, specifically for allergies - brand names Zyrtec and Claritin - are what Dr. Stukus recommends. "I generally recommend start with cetirizine or loratadine.

I think these are very effective options to use, and you can take them on a daily basis or as needed," says Dr. Stukus. Other options he recommends are by prescription only - these include prescription strength antihistamines and steroid nasal sprays.