Occupational asthma due to formaldehyde

Formaldehyde is a low molecular weight chemical and can elicit acute and ch ronic health related problems. Most of the inhaled fomaldehyde is retained in the upper respiratory tract due to its extraordinary solubility. Therefo re, cases of formaldehyde-induced occupational asthma are sporadic despite its widespread use in industrial processes. We herein report upon a case of occupational asthma due to formaldehyde, which was confirmed by workplace challenge including working environmental assessments, and by formaldehyde inhalation challenge using a specially designed closed-circuit apparatus. T o investigate the possible involvement of an IgE-mediated mechanism, both i n vitro and in vivo tests were done. IgE antibody specific for formaldehyde -human serum albumin conjugate (F-HSA) was not detected by ELISA, and no sp ecific cutaneous reactivity to F-HSA was noted by either skin prick or intr adermal test. The patient was diagnosed with formaldehyde-induced occupatio nal asthma not associated with an IgE mediated mechanism.