My husbands has trouble with his ears itching and we have always assumed it is allergies. He has been prescribed Asteline (I might not be spelling that right) nasal spray -- although we have never discussed it with his doctor, he just squirts a little bit in his ears too and it works great at relieving the itch.
On the non-prescription options, I believe it is always considered safe to use hydrogen peroxide (diluted by 50%) in the ears -- my husband uses it full strength on a Q-tip to relieve itching, but on a small child I would add a little bit of water to the peroxide first then dip the Q-tip just to be on the safe side. You can either squirt a little bit in the ear and leave a cotton ball in the ear for 5-10 minutes or just swipe around a little bit with the Q-tip (which, technically is not recommended, since the only place you are supposed to use a Q-tip is on the very outer portion of the ear and not on the inside where it is iching)
On the non-prescription options, I believe it is always considered safe to use hydrogen peroxide (diluted by 50%) in the ears -- my husband uses it full strength on a Q-tip to relieve itching, but on a small child I would add a little bit of water to the peroxide first then dip the Q-tip just to be on the safe side. You can either squirt a little bit in the ear and leave a cotton ball in the ear for 5-10 minutes or just swipe around a little bit with the Q-tip (which, technically is not recommended, since the only place you are supposed to use a Q-tip is on the very outer portion of the ear and not on the inside where it is iching)