"The problem with carpet is you can never get all the dust out," he said.
"In schools, it's tragic, because they wash the carpets right before the kids come to school and that's the most humid time of year, so they never dry out. Then they get moldy."
He said the problem particularly is dangerous for young children, who may be crawling around on the floor.
"I have a particle counter, and it might measure 2,000 or 3,000 particles per cubic foot of air," he said.
"That can go up to 50,000 particles per cubic foot when you tap the carpet."
Atkinson said one of the best things people can do to keep dust mites controlled is to buy allergy-free encasements for mattresses and pillows. Electrostatic filters also have the potential to help.
Another major allergy trigger is pets, Atkinson said. It's one thing to have a pet-free home, but parents should also check classrooms for pets such as gerbils, rats, rabbits or other animals. Fish are fine, he said.
"If you have indoor animals, wash them," he said.
"Once-a-week washing reduces the dander burden by 10 percent, but ideally, keep them outside."
May said people who suffer consistent seasonal symptoms may find it helpful to see a doctor to get tested for specific allergies.
Atkinson said medications offer some relief.
"For years and years, we've had antihistamines, such as Benadryl," he said.
The newest medicine he prescribes is the antihistamine Xyzal. He also prescribes nasal steroid sprays, and for eyes, he recommends antihistamine eye drops.
When nothing else works, people are given allergy shots, he said.
"Once you're under attack, you're in trouble," Atkinson said.
"Cover your mouth or face. Get inside and shower as soon as possible. Saline irrigation may be helpful for some people."Know it: Flu