Risk Factors for Allergies

While many people develop allergies during childhood, you can develop an allergy at any time, even if no one else in your family has one. Some infants are diagnosed with a nasal allergy within the first year of life. Other people develop their first allergic reaction later in life. In most people, nasal allergies appear before age 20. But the onset of symptoms may occur at any age, even 60 or 70, although this is rare.

Factors that can increase your risk for developing nasal allergies include the following:

• Cigarette smoke. Children who grow up in homes with cigarette smoke have a higher risk of developing allergies.
  
  
• Births during high-pollen seasons. Some experts believe babies born during high-pollen seasons may be more sensitive to hay fever allergens later in life.
  
  
• Allergen exposure. Early exposure to allergens like mold, pollen, dust mites, pet dander, cockroaches, and some types of food seems to increase your risk of developing allergies.
  
  
• Being a bottle-fed baby. Studies show that breast-feeding reduces the frequency and severity of allergies in children.
  
  
• Being born prematurely. Premature babies have a higher risk of developing allergies later in life.
  
  
• Having one or more parents who have nasal allergies. Children have a 1 in 3 chance of developing nasal allergies if just one of their parents have allergies. If both have allergies, their risk is nearly 70%.

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Written by Karen Serrano, MD
Emergency Medicine resident at the University of Wisconsin-Madison.

Reviewed by Lisa V. Suffian, MD
Instructor of Clinical Pediatrics in the Division of Allergy and Pulmonary Medicine at Saint Louis Children's Hospital, Washington University School of Medicine
Assistant Clinical Professor in the Department of Pediatrics at Cardinal Glennon Children's Hospital, Saint Louis University
Board certified in Allergy and Immunology

Last updated June 2008