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- Allergy facts
- Allergy overview
- What is an allergy?
- What is an allergy? (Continued)
- What causes allergies?
- What causes allergies? (Continued)
- Who is at risk for allergies and why?
- What are common allergic conditions and what are allergy symptoms and signs?
- Allergic rhinitis (hay fever)
- Allergic eyes (conjunctivitis)
- Eczema (atopic dermatitis)
- Hives (urticaria)
- Allergic shock (anaphylaxis)
- Where are allergens?
- In the Air We Breathe
- In What We Ingest
- Touching Our Skin
- Injected Into Our Body
Who is at risk for allergies and why?
Allergies can develop at any age, and the initial exposure or sensitization period may even begin in while the fetus is in the uterus. Individuals can also outgrow allergies over time. Whereas many children outgrow food allergies, nasal or environmental allergies often develop over time.
Why, you may ask, are some people "sensitive" to certain allergens while most are not? Why do allergic people produce more IgE than those who are nonallergic? Although we certainly do not fully understand why one person develops allergies and another does not, we know there are several risk factors for allergic conditions. Family history, or genetics, plays a large role, with a higher risk for allergies if parents or siblings have allergies. There are numerous other risk factors for developing allergic conditions. Children born via Cesarean section have a higher risk of allergy as compared to children who are delivered vaginally. Exposure to tobacco smoke increases the risk of allergy. Boys are more likely to be allergic than girls. Exposures to antigens, use of antibiotics, and numerous other factors, some of which are not yet known, also contribute to the development of allergies. This complicated process continues to be an area of medical research.