Your best bet in treating allergies is to avoid the substances that trigger symptoms in the first place. These strategies can make a big difference:  
  
Pollen (seasonal allergies)

• It’s hard to keep your child inside, but try to keep him or her inside at least part of the time between 10  a.m. and 5 p.m., when  pollen is at its peak. (Check pollen counts in your area at the website of the  American Academy of Allergy, Asthma and  Immunology  http://www.aaaai.org/nab/index.cfm or at pollencount.com)  
• Have your child spend more time indoors when grass is being mowed, and on cloudy, still days when there is a threat of thunderstorms. There can be added mold or pollen spores right before a thunderstorm.
• Change your child’s clothes and wash his hair after he has played outside for an entire morning or afternoon.
• Close the windows and doors and turn on the fan setting of  your air conditioner, which acts as an air purifier. Clean the AC filters every week or two.

Dust  

• Wipe surfaces with a damp cloth; use a wet mop on floors.
• If you use a forced-air heating system, replace filters frequently, or use an air purifier.
• If possible, avoid wall-to-wall carpeting. If you have carpeting, vacuum it weekly with a HEPA-filter vacuum and keep your child out of the room for at least a half hour afterwards.   
• Use allergy casings on a child’s mattress and pillow, and wash bedding weekly in hot water (at least 130 degrees); that can reduce dust mites by as much as 80 percent.
• While some recommend stuffed animals be banned, naturally that’s a tough position to carry out. A reasonable alternative is to keep the menagerie off the bed and away from your child’s face wherever she’s sleeping. You can also tumble them regularly in the dryer to remove dust, or seal them in a plastic bag for 24 hours to kill dust mites.

Pet dander  

• If you have a family history of allergies, you may decide to put off adopting a pet. But since there’s no way to know when or if your child will develop an allergy to your fuzzy friend, you may also opt to go for it if your child shows no signs of being allergic. Trying to eliminate any and all sources of allergy triggers from your home is pretty much futile, and has been shown to sometimes actually backfire.
• If you already have a pet, wash it regularly and keep it out of your child’s bed or play room.

Mold

• Use exhaust fans in bathrooms to remove moisture and put a dehumidifier in the basement.
• Repair leaks promptly and dry water as soon as you see it.    
• If you smell a musty odor, it’s mold. Remove damaged carpets, rugs or furniture.
• Scrub any mold you see with a bleach-and-water (3/4 cup chlorine bleach to 1 gallon of water) or a commercial mold remover.   
• Keep your child from playing in piles of dead leaves in the fall—they can harbor mold.    

Foods

• Eliminate allergic foods from your child’s diet. That’s easier said than done if your child is allergic to a ubiquitous food like wheat, eggs, or nuts. You’ll need to study food labels and seek out natural and health-food stores, which often stock foods free from common allergy-provoking  foods. The Food Allergy Network has helpful information on how to identify problem ingredients on food labels. If you are bottle-feeding, talk with your pediatrician or allergist about the best brand of formula.