AIRWAY RESPONSE TO FORMALDEHYDE INHALATION IN ASTHMATIC SUBJECTS WITHSUSPECTED RESPIRATORY FORMALDEHYDE SENSITIZATION

The aim of the study was to characterize the mechanism of formaldehyde (FM)-induced nasal ann bronchial response in asthmatic subjects with suspected FM allergy. Ten subjects purported to have FM rhinitis and a sthma and 10 healthy subjects submitted to an inhalation provocation i n an exposure chamber with FM at a dose of 0.5 mg/m(3) over 2 hr. Spir ometry at rest and following bronchial provocation with histamine (PC2 0) were recorded before and after FM inhalation. In addition, FM-speci fic serum IgE antibodies were measured and cellular biochemical, and m ediator changes were assessed in nasal lavage before, and immediately after provocation and at 4 hr and 24 hr later. Provocation with FM cau sed only transient symptoms of rhinitis in both groups. None of the su bjects supposed to have occupational asthma developed clinical symptom s of bronchial irritation. No specific IgE antibodies to FM were detec ted in persons with occupational exposure to FM. No differences in the nasal response to FM were found between subjects reporting to have oc cupational allergic respiratory diseases and healthy, subjects (P > 0. 05). In summary inhaled formaldehyde at a level as low as 0.5 mg/m(3) did not induce a specific allergic response either in the upper or in the lower part of the respiratory tract. Moreover; there is no differe nce in nasal response to FM in asthmatic subjects occupationally expos ed to FM and healthy subjects. (C) 1998 Wiley-Liss, Inc.