Occupational asthma caused by cedar urea formaldehyde particle board.

Two carpenters developed asthma and rhinitis related to occupational exposure to a cedar urea formaldehyde (CUF) particle board. One patient developed nasal and chest symptoms and an equivocal early asthmatic response after CUF sawdust exposure, but not after spruce or western red cedar sawdust exposure; possible late asthmatic response may have been inhibited by beclomethasone treatment. The other patient developed marked nasal and chest symptoms and a dual asthmatic response after CUF exposure, but not after spruce or cedar exposure. Both patients developed increased bronchial responsiveness to inhaled histamine, which persisted for at least six days in the first patient, and which was associated with increased asthmatic symptoms of days' to weeks' duration in both. A previously unexposed asthmatic patient, with more markedly hyperreactive bronchi, developed no symptoms, no change on spirometric testing, and no change in histamine response after CUF exposure. Specific IgE antibodies directed against formaldehyde-human serum albumin conjugate could not be demonstrated using the radioallergosorbent test. This investigation documents the occurrence of occupational asthma caused by urea formaldehyde used as a bonding agent in particle boards. Absence of a response in a previously unexposed, more severe asthmatic patient suggests specific sensitization to some component of the urea formaldehyde resin complex had developed.