Just wait a minute, can you really be allergic to school? Well, kind of. New research published in the May issue of Annals of Allergy, Asthma & Immunology shows that dustless chalk that is being used to keep hands and classrooms clean may cause allergy and asthma symptoms in students that have a milk allergy.
From the press release:
Casein, a milk protein, is often used in low-powder chalk. When milk allergic children inhale chalk particles containing casein, life-threatening asthma attacks and other respiratory issues can occur.
“Chalks that are labeled as being anti-dust or dustless still release small particles into the air,” said Carlos H. Larramendi, MD, lead study author. “Our research has found when the particles are inhaled by children with milk allergy, coughing, wheezing and shortness of breath can occur. Inhalation can also cause nasal congestion, sneezing and a runny nose.”
Milk allergy affects an estimated 300,000 children in the United States, according to the ACAAI. Although it has been believed the majority of children will outgrow milk allergy by age three, recent studies contradict this theory, showing school aged children are still affected. However, 80 percent of children with milk allergy will likely outgrow it by age 16.
“Chalk isn’t the only item in a school setting that can be troublesome to milk allergic students,” said James Sublett, MD, chair of the ACAAI Indoor Environment Committee. “Milk proteins can also be found in glue, paper, ink, and in other children’s lunches.”
Even in the wake of whiteboards, overhead projectors and tablets, chalk is a classroom staple that likely won’t become extinct anytime soon. Parents with milk allergic children should ask to have their child seated in the back of the classroom where they are less likely to inhale chalk dust, advises Sublett.
Abstract of the research:
Background: Nondietary exposure to milk proteins may be a risk for children who do not outgrow milk allergy by school age.
Objective: To study the allergenicity of casein containing chalk.
Methods: A 6-year-old, milk allergic child developed asthma and rhinoconjunctivitis while in school. The suspected cause was dust-free chalk containing casein. To study the relationship of dust-free chalk containing casein with asthma and rhinoconjunctivitis, 13 additional milk allergic patients were studied: 3 school-aged children, 8 preschool-aged infants, and 2 children with outgrown milk allergy. Skin tests and/or specific IgE with chalk and casein were performed. A chalk use test was performed in older children. Milk allergens contained in chalk were characterized by sodium dodecyl sulfate–polyacrylamide gel electrophoresis, immunoblot, and IgE inhibition experiments.
Results: All school-aged, milk allergic children were exposed to chalk and reported symptoms attributed to chalk exposure. The skin test result to chalk was positive in 5 of 12 cases, and the specific IgE test result was positive in all 12 study participants in which it was performed. Casein strongly inhibited the binding of IgE to chalk. Chalk sodium dodecyl sulfate–polyacrylamide gel electrophoresis showed proteins with molecular weight similar to caseins. Immunoblot demonstrated strong binding of IgE to chalk in a blurred pattern and a band at 30 kDa, inhibited by casein. The chalk challenge test result was positive in 2 school-age children who had a positive skin test result to chalk. Their symptoms improved after avoidance of chalk in the school. In 2 other cases in which the challenge test result was negative, chalk was reintroduced without problems.
Conclusion: Inhalation of chalk dust containing casein can induce asthma symptoms in milk allergic patients. Hidden and nondietary sources of exposure should always be considered in food allergic patients.