Environmental Allergy


Envi­ron­men­tal aller­gies, also known as sea­son­al aller­gies, hayfever, or aller­gic rhini­tis, are caused when your immune sys­tem over­re­acts to aller­gen par­ti­cles in the air that you breathe. There are both indoor and out­door envi­ron­men­tal aller­gens that can affect you at any age. 


Envi­ron­men­tal aller­gens can come from a vari­ety of sources and can be found just about any­where. The most com­mon envi­ron­men­tal trig­gers for aller­gies are dust mites, pol­lens from grass­es, trees and weeds, and mold. 

Dust mites are one of the most com­mon indoor aller­gens. They are micro­scop­ic bugs that live in the car­pet and fur­ni­ture of your home. 

Grass­es, trees, and weeds pro­duce pol­lens that trav­el through the air and are inhaled. Pol­lens from trees are typ­i­cal­ly high­er in the Spring, grass­es are high­est in the Sum­mer and weeds in the Fall.

Mold is tiny fun­gi that can be found in soil, plants, rot­ting woods, and damp indoor envi­ron­ments. Mold pro­duces tiny spores that float in the air and are inhaled. 

The two types of envi­ron­men­tal aller­gies are sea­son­al and peren­ni­al. Sea­son­al aller­gies can occur in the Spring, Sum­mer and Fall and are typ­i­cal­ly caused by air­borne mold spores and pollen from trees grass­es and weeds. Peren­ni­al aller­gies occur year-round and are typ­i­cal­ly caused by a sen­si­tiv­i­ty to dust mites, dan­der and mold.


When a per­son sus­cep­ti­ble to envi­ron­men­tal aller­gens inhales them, the body will most com­mon­ly react with the fol­low­ing symptoms:

  • Stuffy nose
  • Run­ny nose or post nasal drainage
  • Itch­ing, usu­al­ly in the nose, mouth, eyes, or throat
  • Red and watery eyes
  • Puffy, swollen eyelids
  • Sneez­ing
  • Cough


To diag­nose an envi­ron­men­tal aller­gy, you can meet with an aller­gist who will dive into your health his­to­ry look­ing for any con­sis­tent trig­gers to deter­mine if your symp­toms are aller­gic or non-aller­gic. Your aller­gist may also rec­om­mend a skin test or blood test to deter­mine any aller­gens that may be affect­ing your system.

Man­age­ment and Treat­ment

The first step in man­ag­ing your envi­ron­men­tal aller­gies is avoid­ance. If pos­si­ble, avoid expo­sure to trig­gers that acti­vate your symp­toms. Some exam­ples of avoidance:

Out­door exposure

  • Stay indoors as much as pos­si­ble when pollen counts are at their peak, usu­al­ly dur­ing the mid­morn­ing and ear­ly evening (this may vary accord­ing to plant pollen), and when wind is blow­ing pol­lens around.
  • Avoid using win­dow fans that can draw pol­lens and molds into the house.
  • Wear glass­es or sun­glass­es when out­doors to min­i­mize the amount of pollen get­ting into your eyes.
  • Don’t hang cloth­ing out­doors to dry; pollen may cling to tow­els and sheets.
  • Try not to rub your eyes; doing so will irri­tate them and could make your symp­toms worse.

Indoor expo­sure

  • Keep win­dows closed and use air con­di­tion­ing in your car and home. Make sure to keep your air con­di­tion­ing unit clean.
  • Reduce expo­sure to dust mites, espe­cial­ly in the bed­room. Use mite-proof” cov­ers for pil­lows, com­forters and duvets, and mat­tress­es and box springs. Wash your bed­ding fre­quent­ly, using hot water (at least 130 degrees Fahrenheit).
  • To lim­it expo­sure to mold, keep the humid­i­ty in your home low (between 30 and 50 per­cent) and clean your bath­rooms, kitchen, and base­ment reg­u­lar­ly. Use a dehu­mid­i­fi­er, espe­cial­ly in the base­ment and in oth­er damp, humid places, and emp­ty and clean it often. If mold is vis­i­ble, clean it with mild deter­gent and a 5 per­cent bleach solu­tion as direct­ed by an allergist.
  • Clean floors with a damp rag or mop, rather than dry-dust­ing or sweeping.

If your symp­toms can­not be well-con­trolled by sim­ply avoid­ing trig­gers, your aller­gist may rec­om­mend med­ica­tions that reduce your symp­toms. They are avail­able in many forms – oral tablets, liq­uid med­ica­tion, nasal sprays and eye­drops. They may also rec­om­mend aller­gy shots to help your sys­tem become more resis­tant to a spe­cif­ic allergen.