Background:Specific inhalation challenge is widely considered as the gold standard for the diagnosis of occupational asthma. Recently some authors reported that specific inhalation challenge is needed only in a minority of cases, mainly because its limited availability in some regions. Objective:The objective of this study is to compare the results of specific inhalation challenge with other tools used in the diagnosis of occupational asthma Methods:We investigated 29 subjects referred to our center by occupational physician or by Italian workers‘ compensation insurance.All the patients reported work related symptoms of asthma and have performed pulmonary function tests, including methacoline challenge or bronchodilator challenge, prick test for common airborne allergens and sometimes specific prick test.Specific inhalation challenge were performed in an exposure chamber, according to the most recent guidelines. Results: Only 6 out of 29 patients showed a significant decrease in FEV1 at the specific inhalation challenge. No differences were found between patients with a positive specific inhalation challenge and the others in terms of age, sex, smoking, atopy, FEV1 and vital capacity before the challenge, bronchial hyperresponsiveness, molecular weight of challenge substances. Conclusions: This study did not show any factor that could be predictive of a positive response to a specific inhalation challenge.Given the small number of subjects any strong conclusion should be avoided; anyway our results could indicate that an history of work-related asthma, even if completed by respiratory and allergy tests, is not sufficient for the diagnosis of occupational asthma.
Is the specific inhalation challenge always needed for the diagnosis of occupational asthma? A pilot study
N. Murgia
;
2009
Abstract
Background:Specific inhalation challenge is widely considered as the gold standard for the diagnosis of occupational asthma. Recently some authors reported that specific inhalation challenge is needed only in a minority of cases, mainly because its limited availability in some regions. Objective:The objective of this study is to compare the results of specific inhalation challenge with other tools used in the diagnosis of occupational asthma Methods:We investigated 29 subjects referred to our center by occupational physician or by Italian workers‘ compensation insurance.All the patients reported work related symptoms of asthma and have performed pulmonary function tests, including methacoline challenge or bronchodilator challenge, prick test for common airborne allergens and sometimes specific prick test.Specific inhalation challenge were performed in an exposure chamber, according to the most recent guidelines. Results: Only 6 out of 29 patients showed a significant decrease in FEV1 at the specific inhalation challenge. No differences were found between patients with a positive specific inhalation challenge and the others in terms of age, sex, smoking, atopy, FEV1 and vital capacity before the challenge, bronchial hyperresponsiveness, molecular weight of challenge substances. Conclusions: This study did not show any factor that could be predictive of a positive response to a specific inhalation challenge.Given the small number of subjects any strong conclusion should be avoided; anyway our results could indicate that an history of work-related asthma, even if completed by respiratory and allergy tests, is not sufficient for the diagnosis of occupational asthma.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
