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Inhaled formaldehyde exposure: effect on bronchial response to mite allergen in sensitized asthma patients
Author(s) -
Casset A.,
Marchand C.,
Purohit A.,
Le Calve S.,
UringLambert B.,
Donnay C.,
Meyer P.,
De Blay F.
Publication year - 2006
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/j.1398-9995.2006.01174.x
Subject(s) - asthma , inhalation , medicine , allergen , mite , formaldehyde , allergy , inhalation exposure , immunology , placebo , anesthesia , chemistry , pathology , botany , alternative medicine , organic chemistry , biology
Background: Formaldehyde, an indoor air pollutant, is known to be an irritant and an etiologic factor in occupational asthma. An epidemiologic study suggests that it may also increase the risk of childhood asthma for concentrations above 60 μ g/m 3 . Aim: To evaluate the influence of pre‐exposure to low‐dose formaldehyde (100 μ g/m 3 in 30 min according to the World Health Organization's recommended maximum value for indoor environments) on bronchial response to Dermatophagoides pteronyssinus. Method: Nineteen asthmatic subjects were included. Each subject underwent a mite allergen bronchial challenge test immediately after a standardized exposure in a chamber to formaldehyde or air (random order). Induced sputum were collected 24 h before and after mite challenge. Results: After formaldehyde inhalation, patients developed an immediate bronchial response at a significantly lower dose of mite allergen than after air exposure (the geometric mean PD 20 for Der p 1 was 34.3 ng after formaldehyde and 45.4 ng after placebo, P = 0.05). The late‐phase reaction, expressed as the maximum fall in forced expiratory volume in 1 s (FEV 1 ) from baseline, was significantly higher after formaldehyde (15% vs 11%, P = 0.046). Conclusion: Our study demonstrated that exposure to low levels of formaldehyde significantly enhanced bronchial responsiveness to mite allergen in mite‐sensitized subjects with asthma.