Watch CBSN Live

Dustless chalk may cause health woes in milk-allergic kids

"Anti-dust" chalk may cause allergy symptoms in children who are allergic to milk.

A new study published in the May issue of Annals of Allergy, Asthma & Immunology shows that dust-free chalk, which is made from a milk protein called casein, may provoke asthma attacks and other respiratory symptoms in children who are allergic to milk.

"Chalks that are labeled as being anti-dust or dustless still release small particles into the air," lead author Dr. Carlos H. Larramendi, said in a press release. "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."

About 300,000 children in the U.S. are allergic to milk, according to the American College of Allergy, Asthma and Immunology (ACAAI). Most children outgrow their milk allergy by the age of three, and 80 percent will not have it by the time they are 16. However, the study authors point out that recent studies have shown that many school-aged kids may still be allergic to dairy.

Researchers identified a 6-year-old milk allergic child who had asthma and rhinoconjunctivitis, a condition that causes symptoms like nasal congestion, runny nose, post-nasal drip, red eyes and sneezing. They then found 13 more children who currently or previously had milk allergies: three school-aged children, eight preschool-aged infants and two children who had outgrown their milk allergy.

The researchers conducted skin tests and immunoglobulin E (IgE) blood tests on the kids after instructing them to use the chalk. IgE tests looks at one of the five kinds of antibodies --immune system responses -- that are usually found in the lungs, skin, and mucous membranes.

All the school-aged, milk allergic children who were exposed to the chalk showed symptoms. The allergy skin test was positive in 5 out of the 12 cases, and the IgE test was positive in all cases. Two of school-aged children who had a positive skin reaction to the chalk also had allergic symptoms when using the chalk.

They discovered that casein prevented IgE from binding to chalk, meaning the antibodies were unable to protect the child from the allergic reaction.

The test was conducted in Spain, so Dr. Clifford Bassett, the medical director of Allergy and Asthma Care of New York, wrote in an article in Fox News that the chalk formula may not contain the same amount of casein as the products sold in the U.S. Also, the participant pool was rather small, and the children were relatively young. Bassett suggested that if a child has allergies or respiratory symptoms, parents should take them to an allergist who can help them come up with a plan to treat allergic reactions.

Dr. James Sublett, chair of the ACAAI Indoor Environment Committee, said in a press release that if parents know that their child has a milk allergy, they should ask the teacher to sit them in the back of the classroom so they don't inhale the dustless chalk. But, it's not only anti-dust chalk that contains milk products: Glue, paper, ink and other children's lunches may also contain the substance.

"Teachers should be informed about foods and other triggers that might cause health problems for children," Sublett said. "A plan for dealing with allergy and asthma emergencies should also be shared with teachers, coaches and the school nurse. Children should also carry allergist prescribed epinephrine, inhalers or other life-saving medications."

View CBS News In