Q: I’ve recently read that asthma inhalers can contain a small amount of milk protein. Since my child has milk allergy and asthma, I’m worried. Is this true and how can she avoid the exposure?
Dr. Sharma: It is true that some asthma inhalers  contain lactose, and as a result, contain trace amounts of associated milk protein.
Talk to your child’s allergist to determine for sure whether her inhaler contains lactose, since not all of them do. For example, some dry powder inhalers may contain lactose, whereas none of the metered-dose inhalers have it.
Whether this trace amount of milk protein in some inhalers is enough to trigger a reaction remains somewhat uncertain. Each person with a milk allergy  has a different degree of sensitivity to milk. For most people with milk allergy, the trace amount of milk in an inhaler would probably not be enough to cause a reaction.
However, there have been a few reported cases of allergic reactions to dry powder inhalers in people with severe milk allergy. It’s possible that a trace amount of milk protein might pose more risk when it is inhaled directly into the airways compared to when it is eaten and altered by digestion.
Given all of these considerations, it would be best to discuss your child’s specific case with her allergist so you can decide together on the best asthma medication plan for her.
Dr. Sharma is an allergist, clinical researcher and assistant professor of pediatrics. He is Associate Chief of the Division of Allergy and Immunology at Children’s National Medical Center in Washington D.C. and Director of the Food Allergy Program. He co-authors “The Food Allergy Experts” column in the American Edition of Allergic Living  magazine. Questions submitted below will be considered for answer in the magazine.