Nuts are a common cause of food allergies and in some cases provoke allergic reactions simply through inhalation of tiny airborne particles. Airborne nut allergies are the basis for prohibition of nuts and nut products in many schools and public places. In extreme cases, a single nut in the same room as a highly allergic individual may trigger reactions including anaphylaxis, a deadly shutdown of vital bodily functions.
Causes
An allergic reaction caused by airborne exposure is due to inhalation of the dust of the allergen. In addition to raw nuts themselves, products made with nuts, such as peanut oil or nut flours, may cause allergic reactions. Many conditions may contribute to the likelihood of developing a nut allergy. Age is one factor, as allergies are generally more common among children, toddlers and infants. Older individuals may also develop a recurring outbreak of peanut allergies if they had them as children. Having allergies to other foods or substances may increase your chances of getting a nut allergy. Likewise, if family members have allergies, you're more likely to develop one.
Possible Effects
Peanuts and tree nuts are the allergens that most often cause anaphylaxis, a deadly condition in which the body overreacts to harmful foreign substances by shutting down vital systems. In less serious cases, allergic effects may include skin conditions such as redness, hives or itching; digestive problems including nausea, vomiting or diarrhea; and respiratory difficulty with a tightening of the chest and wheezing.
Precautions
To avoid harmful effects on individuals with airborne nut allergies, many public institutions forbid nut substances. Given the higher frequency of food allergies among children, schools most frequently set restrictions on nuts. School policies may include rules against bringing in peanuts or peanut butter. Other policies may include rules against sharing food or bringing in food for class parties. As well as preventing the risk of allergic reactions, such practices are often adopted to reduce the risk of lawsuits.
Controversy
While airborne nut allergies can pose serious health consequences for those affected, the "nut-free zone" rules established at some schools have fallen under scrutiny. In a 2009 article for "Time," reporter Tiffany Sharples reviews the work of Harvard Professor Nicholas Christakis, who reports that each year, about 150 people in the U.S. die of allergic reactions, compared with 100 people who die of lightning strikes, 1,300 people who die from gun accidents and 45,000 who die in car crashes. Dr. Robert Wood, chief of Pediatric Allergy and Immunology at Johns Hopkins Children's Center, says most policies tend toward over-protection and recommends different approaches for preschools and elementary schools, incorporating greater precautions for children at younger ages.
References
- MedlinePlus: Food Allergy
- MayoClinic.com; Peanut Allergy: Risk Factors; April 2010
- MayoClinic.com; Peanut Allergy: Symptoms; April 2010
- NetWellness; Peanut Allergy in the School Environment: Myths and Facts: Part 1 of a 2-Part Series; Jill F. Killanowski, Ann Stalter
- "Time"; Have Americans Gone Nuts Over Nut Allergies?; Tiffany Sharples; January 2009
