Factors contributing to development of allergy.

1. Predisposing factors:

   • The Atopic Condition. Some people have a genetic predisposition to develop allergic diseases. This predisposition is inheritable. It is more probable that a child is allergic, when other members of the family (mother, father, siblings) are allergic.

   • Gender. Some allergic diseases (asthma) are more frequent in boys than in girls.

2. Causal factors è ALLERGENS

   • Indoor allergens:

     • House dust mites

     • Molds

     • Pets dander

     • Cockroaches

   • Outdoor allergens

     • Molds

     • Pollens

     • Animal dander

   • Occupational Allergens è They affect adults who are exposed to some substances because of their jobs (flour in the case of bakers, wood dust in carpenters,…)

3. Coadjuvating and Triggering Factors: These factors do not cause allergy by themselves, but they facilitate that someone becomes allergic to factors described above, or they can trigger symptoms in an already allergic person:

   • Air pollution

   • Cold air

   • Cigarette smoke

   • Exercise

   • Respiratory infections