Contamination of nebulizers with environmental allergens

Background: A previous article described cockroach allergen in the nebulizer reservoir of an asthmatic patient who experienced a life-threatening exacerbation after nebulizer use. Objective: To determine whether indoor allergens can be measured in home nebulizers. Methods: As part of a large study examining nebulizer use in underserved asthmatic children, visiting nurses replaced nebulizer sets in patients' homes. Twenty used sets were randomly selected for analysis, without linkage to clinical or home environmental data. Nebulizer reservoirs and negative controls (buffer and albuterol) were extracted overnight with 2 mL of buffer. For positive controls, nebulizer sets were placed in homes with cats and dogs, and other reservoirs were intentionally contaminated with cat (Fel d 1), dog (Can f 1), cockroach (Bla g 1 and Bla g 2), and mouse (Mus m 1) skin test solutions. Extracts were tested for allergens in a masked manner using enzyme-linked immunosorbent assay. Results: Of 17 reservoirs with adequate specimens for allergen detection, 5 (29%) had measurable levels for at least 1 of 5 allergens tested. One reservoir had measurable Can f 1, 2 had Bla g, 3 had Mus m 1, and none had Fel d 1 allergen. Two of 3 homes with cats where nebulizer setups were placed had measurable Fel d 1 in the reservoir, and 1 of 2 homes with dogs had measurable Can f 1. Reservoirs kept in sealed plastic bags had no detectable allergen. Conclusions: Indoor allergens can be found in the nebulizer equipment of children with asthma, with the potential for adverse consequences. Storing nebulizer sets in sealed plastic bags may prevent contamination.