Abstract
INTRODUCTION: It is generally agreed that the best treatment after diagnosis of occupational asthma (OA) is avoidance of exposure to the causal agent. However, recent meta-analyses have raised doubts about this conclusion. The aim of the present study is to assess the evolution of OA depending on whether or not the patient avoids exposure.
METHODS: Multicentre, cross-sectional clinical follow-up study in patients diagnosed with OA using a specific inhalation challenge (SIC) between January 2000 and December 2009. Patients with this diagnosis received the following examinations on the same day: clinical interview, physical examination, forced spirometry, methacholine test and determination of total IgE and IgE specific to the causal agent. CIinical improvement, deterioration or no change were defined according to the changes seen in the GINA severity scale at the time of diagnosis.
RESULTS: Of the 73 patients finally included, 55 had totally ended exposure and 18 continued. The mean time elapsed since diagnosis was 48 months (range: 12 – 123). Forty-two per cent of patients who avoided exposure improved clinically, 38% presented no change, and 14% deteriorated. In the patients who did not avoid exposure improvement was recorded in 22%, deterioration in 17% and no change in 61%. No significant differences in methacholine PC20 or FEV1 were detected between both groups.
CONCLUSIONS: Avoiding exposure to the causal agent in patients with OA does not seem to improve prognosis in this disease.
Project partially funded by Ciber de Enfermedades Respiratorias (CibeRes).