Sir.—I read with interest the article by Pérez-Soler1 in the September 1989 issue of AJDC. In 1985 my coauthors and I2 described, under the rubric "plastic bronchitis," five children from the United States, Japan, and Saudi Arabia who expectorated large, branching, bronchial casts. Four of our five patients had histories of wheezing or allergy. In clinical respects our patients appear to be similar to those of Pérez-Soler, with the exception of our patient 1, an 8-year-old boy with tricuspid atresia who was neither allergic nor asthmatic. Our other patients were all aged 5 years or younger.
A prominent feature of casts in Pérez-Soler's series was the presence of metaplastic squamous epithelial cells. In our patients the casts were predominantly mucoid material with variable quantities of inflammatory cells. Are plastic bronchitis and Pérez-Soler's "cast bronchitis" the same condition, or do the differing compositions of the casts serve to