Over three quarters of new diagnoses were in children under two years old, and about 70 percent were boys.
It’s not clear why the food allergy has become more common.
“The leading theory is about hygiene - with less infection thanks to city living, smaller families, vaccines, sanitation, antibiotics, etc., the immune system is less ‘busy’ with germs and may become more prone to attack harmless food proteins,” said Dr. Scott Sicherer, a pediatrics professor at Mount Sinai School of Medicine in New York, in an email.
Sicherer, who did not participate in the latest research, said another theory is that kids receive less vitamin D from sunlight because they are indoors or use sunscreen, and that could alter their immune system responses.
But these remain theories, and no one has proven why allergies are increasing.
Because peanut reactions can be severe, even lethal, measures to protect allergy sufferers from accidental exposure are becoming more common too, with peanut bans on airplanes, peanut-free sections of baseball stadiums and “school safe” packaged snacks manufactured in nut-free environments.
Gupta said it’s important for parents to be aware of the potential signs of a food allergy, including hives, respiratory symptoms and digestion problems.
What is a peanut allergy?
A peanut allergy is a reaction that occurs when your body mistakenly identifies peanuts as harmful substances. When you eat peanuts or food containing peanuts, your immune system-the body’s natural defense system that fights infections and diseases-overreacts and can cause a serious, even life-threatening response.
What causes a peanut allergy?
An allergic reaction occurs when your immune system overreacts and releases chemicals, including histamine, into your blood. These chemicals can affect different tissues in the body, such as the skin, eyes, nose, airways, intestinal tract, lungs, and blood vessels. It’s not clear why peanuts trigger this response in some people.
What are the symptoms?
Symptoms of peanut allergy can range from mild to life-threatening. If you have a mild reaction, you may get a stomachache, a runny nose, an itchy skin rash, hives, or tingling in your lips or tongue. If your reaction is worse, you may develop additional symptoms such as a tight throat, hoarse voice, wheezing, coughing, feeling sick to your stomach, vomiting, belly pain, and diarrhea. Your symptoms may start from within a few minutes to a few hours after eating peanuts or peanut products.
People who are allergic to peanuts may have a life-threatening reaction called anaphylaxis. Symptoms of anaphylaxis can include problems breathing and swallowing, vomiting and diarrhea, dizziness, dangerously low blood pressure, swelling of the lips, tongue, throat, and other parts of the body, and loss of consciousness. If not treated, death can result. Anaphylaxis usually occurs within minutes but can occur up to several hours after eating peanuts or peanut products.
She also urges parents to see a doctor if they suspect their child has an allergy.
People with peanut allergy should know about foods to avoid, as many who are allergic to peanuts are allergic to other nuts like walnuts, cashews or brazil nuts.
Doctors admit that the ubiquity of foods to avoid makes avoidance difficult and accidental ingestion common. Many of these foods are also popular with children, making it difficult to prevent contact or consumption. Good substitutes are available, however, for foods such as peanut butter.
Be sure to avoid foods that contain any of the following ingredients:
- cold pressed, expressed, or expelled peanut oil
- ground nuts
- mixed nuts
- Nu-Nuts® artificial nuts
- peanut butter
- peanut flour
Foods that may indicate the presence of peanut protein include:
- African, Chinese, Thai, and other ethnic dishes
- baked goods
- chili, spaghetti sauce
- chocolate (candy, candy bars)
- egg rolls
- hydrolyzed plant protein
- hydrolyzed vegetable protein
- ice creams, frozen yogurts, tofutti
SOURCE: The Journal of Allergy and Clinical Immunology, online September 3, 2012
Peanut allergy diagnoses among children residing in Olmsted County, Minnesota
Residents of Olmsted County from January 1, 1999, through December 31, 2007, who received medical care at a Rochester Epidemiology Project facility and provided research authorization were eligible for the study. A medical chart review of 547 potential diagnoses resulted in 244 prevalent and 170 incident cases. Annual rates, crude and adjusted for age and sex, were standardized with the use of the indirect method to the Olmsted County population data in 1999. Incidence rate ratios were estimated with Poisson regression.
The prevalence in 2007 was 0.65%. Female children were less likely to be diagnosed than male children (incidence rate ratio = 0.18; 95% CI, 0.07-0.48). Children aged birth to 2 years were significantly more likely to be diagnosed than older children aged 3-17 years (incidence rate ratio = 0.001; 95% CI, 0.0004-0.004). A significant 3-fold increasing trend was observed in diagnoses over time from 2.05 cases per 10,000 children in 1999 to 6.88 cases per 10,000 in 2007.
Peanut allergies are an increasing concern in Olmsted County, Minnesota, as indicated by a 3-fold increase in diagnoses from 2.05 per 10,000 children in 1999 to 6.88 per 10,000 children in 2007.
Maria Rinaldi, Lisa Harnack, Charles Oberg, Pamela Schreiner, Jennifer St. Sauver, Lori L. Travis
The Journal of Allergy and Clinical Immunology - 03 September 2012 (10.1016/j.jaci.2012.07.042)