This consensus statement provides practical recommendations for specific inhalation challenge (SIC) in the diagnosis of occupational asthma. They are derived from a systematic literature search, a census of active European centres, a Delphi conference and expert consensus. This article details each step of a SIC, including safety requirements, techniques for delivering agents, and methods for assessing and interpreting bronchial responses. The limitations of the procedure are also discussed.Testing should only be carried out in hospitals where physicians and healthcare professionals have appropriate expertise. Tests should always include a control challenge, a gradual increase of exposure to the suspected agent, and close monitoring of the patient during the challenge and for at least 6 h afterwards. In expert centres, excessive reactions provoked by SIC are rare.A positive response is defined by a fall in forced expiratory volume in 1 s o15% from baseline. Equivocal reactions can sometimes be clarified by finding changes in nonspecific bronchial responsiveness, sputum eosinophils or exhaled nitric oxide. The sensitivity and specificity of SIC are high but not easily quantified, as the method is usually used as the reference standard for the diagnosis of occupational asthma. @ERSpublications ERS Task Force: a statement on specific inhalation challenges in the diagnosis of occupational asthma

This large cohort study describes distinct phenotypic profiles in OA caused by HMW and LMW agents. There is a need to further explore differences in underlying pathophysiological pathways and outcome after environmental interventions.

Background Dyspnea is a prominent symptom in asthma. The Dyspnea-12 (D-12), an instrument that quantifies breathlessness using 12 descriptors that tap the physical and affective aspects, has shown promise for the measurement of dyspnea in cardiorespiratory disease. Objective We report the results of a study designed to test the validity and reliability of the D-12 in a population of patients with asthma. Methods This cross-sectional study included 102 patients with asthma. Subjects completed the D-12, Hospital Anxiety and Depression Scale (HAD), St George’s Respiratory Questionnaire (SGRQ), MRC scale. Confirmatory factor analysis confirmed the two-component structure of the D-12 (i.e. 7 items that tap the Physical aspects of breathlessness and 5 items that tap the Affective aspects). Results The D-12 subscales had excellent internal reliability (Cronbach’s alpha for the ‘Physical’ score was 0.94 and the Affective score was 0.95). The D-12 Physical component was more strongly correlated with SGRQ Symptoms (r = 0.648), SGRQ Activities (r = 0.635) and MRC grade (r = 0.636), while the Affective component was more strongly correlated with SGRQ Impacts (r = 0.765) and HAD scores (anxiety r = 0.641 and depression r = 0.602). Conclusion This study supports validity of the D-12 for use in the assessment of dyspnea of patients with asthma. It assesses one of the most pertinent symptoms of asthma from two viewpoints -physical and affective.

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Objective To examine the association of adult onset asthma with lifetime exposure to occupations and occupational exposures. Methods We generated lifetime occupational histories for 9488 members of the British 1958 birth cohort up to age 42 years. Blind to asthma status, jobs were coded to the International Standard Classification of Occupations 1988 and an Asthma Specific Job Exposure Matrix (ASJEM) with an expert re-evaluation step. Associations of jobs and ASJEM exposures with adult onset asthma were assessed in logistic regression models adjusting for sex, smoking, social class at birth and childhood hay fever. Results Of the 7406 cohort members with no asthma or wheezy bronchitis in childhood, 639 (9%) reported asthma by age 42 years. Adult onset asthma was associated with 18 occupations, many previously identified as risks for asthma (eg, farmers: OR 4.26, 95% CI 2.06 to 8.80; hairdressers: OR 1.88, 95% CI 1.24 to 2.85; printing workers: OR 3.04, 95% CI 1.49 to 6.18). Four were cleaning occupations and a further three occupations were likely to use cleaning agents. Adult onset asthma was associated with five of the 18 high-risk specific ASJEM exposures (flour exposure: OR 2.12, 95% CI 1.17 to 3.85; enzyme exposure: OR 2.32, 95% CI 1.22 to 4.42; cleaning/disinfecting products: OR 1.67, 95% CI 1.26 to 2.22; metal and metal fumes: OR 1.45, 95% CI 1.02 to 2.07; textile production: OR 1.71, 95% CI 1.12 to 2.61). Approximately 16% (95% CI 3.8% to 27.1%) of adult onset asthma was associated with known asthmagenic occupational exposures. Conclusions This study suggests that about 16% of adult onset asthma in British adults born in the late 1950s could be due to occupational exposures, mainly recognised high-risk exposures.