Biological washing powders as allergens

EDITOR,—A paper by me1 is cited by P J Rees in the reply to a query on whether biological washing powders might be a new allergen.2 Rees states that I reported late onset asthma in workers in factories producing these powders. In fact, the proteolytic enzyme was found to be a potent respiratory sensitiser, causing immediate and late asthma mediated by IgE in both atopic and non-atopic subjects, few of whom had had asthma …