Use of low-dust chalk can cause asthma and allergy symptoms in children with milk allergy, a study by Spanish researchers states.

A milk protein, casein that is also found in low-dust chalks can lead to respiratory problems in milk-allergic children when they inhale chalk particles, states the study published in the May issue of Annals of Allergy, Asthma & Immunology, the scientific journal of the American College of Allergy, Asthma and Immunology (ACAAI).

"Chalks that are labeled as being anti-dust or dustless still release small particles into the air," said Dr. Carlos H. Larramendi, lead author of the study. He explained that the research found that if children with milk allergy inhale the chalk-dust they may suffer from coughing, wheezing and shortness of breath. It may also cause nasal congestion, sneezing and a runny nose.

According to ACAAI, around 300,000 U.S. children (2.5 percent) are allergic to milk. However, it is unclear if the low-dust chalk powder contains cow's milk protein that leads to respiratory problems in children.

Dr James Sublett of the ACAAI said that casein can also be found in glue, paper, ink and other children's lunches. However, the study focused on a small group of children allergic to cow milk.

The study also said that although the children are at risk of getting respiratory problems through chalk powder, oral consumption of such allergic proteins is also a major concern.

The allergies can be caused through food or skin contact and inhalation and it is important that people are aware about its consequences.

Dr Sublett advised that parents of milk allergic children should request that their child be seated away from the chalk dust. This way they have less chances of inhaling the chalk-dust. "Teachers should be informed about foods and other triggers that might cause health problems for children," he 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."