There are many excellent web-based support sites for persons who suspect they have allergies and want to learn more about them and controlling airborne allergen triggers.
Centers for Disease Control (CDC) Environmental Health
The National Institute of Environmental Health Sciences
American Academy of Allergy, Asthma and Immunology
Asthma and Allergy Foundation of America
Allergy and Asthma Network / Mothers of Asthmatics, Inc.
U.S. Environmental Protection Agency
MaryPaul Contract Microbiological Laboratories