Correspondence

LEGO Asthma

N Engl J Med 1996; 334:406-407February 8, 1996

Article

To the Editor:

Inhalation of foreign bodies by children is common yet often missed.1-3 We report a case of inhalation of a LEGO piece that was difficult to identify.

A five-year-old boy presented with a cough of two months' duration that was precipitated by exercise but also occurred at night. His father had had asthma as a child. The boy had seen an otolaryngologist and a pediatrician, both of whom suspected asthma. On further questioning, the father remembered that the boy had swallowed a LEGO piece four months earlier. He was in no distress, but auscultation revealed widespread expiratory rhonchi.

The boy received an oral corticosteroid for five days and an inhaled corticosteroid and beta-adrenergic agonist for one month with symptomatic improvement, but bilateral expiratory rhonchi persisted. A chest film obtained at this time was normal. A second chest film, obtained with two sample LEGO pieces of the type that the boy might have swallowed placed on his left shoulder, was similar in appearance, indicating that the LEGO pieces were radiolucent. Computed tomographic scanning of the chest, fluoroscopy, barium-swallow studies, viral-antibody studies, measurement of serum IgE concentrations, and aeroallergen-specific IgE assays (Phadiatop) were all normal.

A technetium-99m diethylenetriamine penta-acetic acid aerosol ventilation scan and a technetium-99m macroaggregated-albumin perfusion scan both showed very poor visualization of the left lung, indicating localized obstruction of the left main bronchus (Figure 1AFigure 1Posterior Views of a Ventilation Scan (Panel A) and a Perfusion Scan (Panel B) Showing Decreased Ventilation and Perfusion of the Left Lung and a Photograph of the LEGO Piece (Panel C) Subsequently Retrieved from the Boy's Left-Main-Stem Bronchus., Figure 1B, and Figure 1C). A cylindrical 0.5-cm LEGO piece was then removed from the left-main-stem bronchus by rigid bronchoscopy. The boy's cough disappeared. Nine months later, he remained asymptomatic.

LEGO is a popular toy sold throughout the world. Inhalation of LEGO pieces is probably rare. Since LEGO pieces are inert and radiolucent, however, we speculate that there may be inhaled pieces lying unobtrusively in children's airways, causing minimal episodic symptoms that masquerade as mild cases of asthma. In the light of our experience, the manufacturer might consider making some of the smaller LEGO pieces radiopaque.

Robert Tseng, F.R.C.P.
688 Nathan Rd., Kowloon, Hong Kong

Ian Stewart, F.R.C.R.
Andrew Van Hasselt, M.D.
Chinese University of Hong Kong, Shatin, N.T., Hong Kong

3 References

1. 1

   Haines JD Jr. Wheezing as a sign of foreign-body aspiration in infants and children. Postgrad Med 1991;90:153-154
   Web of Science | Medline

2. 2

   Linegar AG, von Oppell UO, Hegemann S, de Groot M, Odell JA. Tracheobronchial foreign bodies: experience at Red Cross Children's Hospital, 1985-1990. S Afr Med J 1992;82:164-167
   Medline

3. 3

   Mu L, He P, Sun D. Inhalation of foreign bodies in Chinese children: a review of 400 cases. Laryngoscope 1991;101:657-660
   Web of Science | Medline

Author/Editor Response

The above letter was referred to LEGO Systems, whose president offers the following reply:

To the Editor: The safety and well-being of children are of utmost concern to LEGO Systems. All LEGO toys meet or exceed all federal and industrial safety requirements for toys.

Tseng et al. imply that the radiolucence of small plastic toys is an important safety hazard that should be addressed by adding substances to make the toys radiopaque. As the medical community is aware, most foreign objects aspirated by children are common household substances other than toys, especially food items such as peanuts and raisins.

Industrial research has determined that the most feasible method of making plastic materials radiopaque is to add barium sulfate. LEGO Systems has tried adding barium sulfate to ABS plastic (the material making up 80 percent of LEGO elements). Unfortunately, this addition causes the mechanical characteristics of the plastic to degrade, making it brittle and more likely to shatter, which would reduce the safety and durability of our products. In addition, in its impure forms, barium sulfate is toxic because of the presence of barium ions. Although pharmaceutical-grade barium sulfate has proved valuable in controlled medical circumstances, there has been little research on the environmental and toxicologic consequences of adding barium sulfate to injection-molded plastic toys.

On the basis of these considerations, LEGO Systems has decided not to make its products radiopaque. We are, however, continuing to investigate solutions to this problem through research and are monitoring developments in the imaging field.

Peter Eio
LEGO Systems, Enfield, CT 06083-1600