title: Evolution of occupational asthma: does cessation of exposure really improve prognosis?
abstract: OBJECTIVE
  To assess the evolution of occupational asthma (OA) depending on whether the patient avoids or continues with exposure to the offending agent.
  
  
  METHODS
  Study in patients diagnosed with OA using a specific inhalation challenge. Patients underwent the following examinations on the same day: clinical interview, physical examination, forced spirometry, methacholine test and determination of total IgE. Clinical improvement, deterioration or no change were defined according to the changes seen on the GINA severity scale at the time of diagnosis.
  
  
  RESULTS
  Of the 73 patients finally included, 55 had totally ended exposure and 18 continued to be exposed at work. Clinical improvement was observed in 47% of those who had terminated exposure and in 22% of those who remained exposed; clinical deterioration was observed in 14% and 17% respectively (p = 0.805). Logistical regression analysis, including the type of agent and the persistence or avoidance of exposure among the variables, did not show any predictive factors of clinical evolution. Similarly, the changes in FEV1 and in bronchial hyperresponsiveness were not associated with the avoidance or continuation of exposure to the causative agent.
  
  
  CONCLUSIONS
  Avoiding exposure to the causative agent in patients with OA does not seem to improve prognosis in this disease. Despite these findings, there is insufficient evidence to recommend a change in current management guidelines.
authors.affiliation: Servicio de Neumología, Hospital Vall d'Hebron, Barcelona, Spain; Ciber Enfermedades Respiratorias (CibeRes), Spain. Electronic address: xmunoz@vhebron.net.
authors.forename: X
authors.initials: X
authors.lastname: Munoz
authors.affiliation: Servicio de Neumología, Hospital Vall d'Hebron, Barcelona, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Viladrich
authors.affiliation: Ciber Enfermedades Respiratorias (CibeRes), Spain; Servicio de Alergia, Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: Manso
authors.affiliation: Ciber Enfermedades Respiratorias (CibeRes), Spain; Servicio de Inmunología, IIS Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: V
authors.initials: V
authors.lastname: del Pozo
authors.affiliation: Ciber Enfermedades Respiratorias (CibeRes), Spain; Department of Allergy, Hospital La Paz Institute for Health Research (IdiPAZ), Madrid, Spain.
authors.forename: S
authors.initials: S
authors.lastname: Quirce
authors.affiliation: Servicio de Neumología, Hospital Vall d'Hebron, Barcelona, Spain; Ciber Enfermedades Respiratorias (CibeRes), Spain.
authors.forename: M J
authors.initials: MJ
authors.lastname: Cruz
authors.affiliation: Departamento de Estadística, Universidad de Barcelona, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Carmona
authors.affiliation: Departamento de Estadística, Universidad de Barcelona, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Sánchez-Pla
authors.affiliation: Ciber Enfermedades Respiratorias (CibeRes), Spain; Servicio de Alergia, Fundación Jiménez Díaz, Madrid, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Sastre
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D059366:Asthma, Occupational / Q000503:physiopathology / Q000517:prevention & control*; D001985:Bronchial Provocation Tests / Q000379:methods; D003430:Cross-Sectional Studies; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure / Q000009:adverse effects / Q000517:prevention & control*; D011379:Prognosis; D012720:Severity of Illness Index; D013147:Spirometry / Q000379:methods; D014797:Vital Capacity / Q000502:physiology; D055815:Young Adult
keywords: High molecular weight; Low molecular weight; Specific inhalation challenge