I'm sharing this in case anyone else's child might unknowingly be suffering from allergies.
My nearly 3-year-old went through a hitting spree recently--for 10 days, day care reports were 'aggressive', 'hitting', and 'talking back'. I know some of this is normal, but the duration of the bad behavior had me worried. Out of desperation I finally took him to the doctor. He had an infection in one ear, but more significant to the doctor were the allergy 'shiners' under both his eyes. He started us on a course of Zyrtec and Motrin to help with the allergy symptoms and pain (both at night). After only a few days it was clear that Michael had been miserable with allergies. He's back to his usual cheerful--energy-bound--self! Without the tell-tale adult symptoms that have me reaching for the Claritin, like sneezing and itching, I didn't realize that my little one was also suffering.