Upper airway and eye involvement in polyurethane shoe sole production workers.

OBJECTIVES: This cross-sectional study was aimed to investigate the prevalence of work-related upper and lower airway and eye symptoms in 118 workers in polyurethane shoe soles (PSS) production. METHODS: Workplace monitoring of methylene diphenyl diisocyanate (MDI) and solvents was performed. Subjects completed a study-specific questionnaire and underwent anterior rhinoscopy, skin prick tests for common aeroallergens, spirometry, nasal peak inspiratory (NPIF) and expiratory flow (NPEF). RESULTS: MDI and solvent levels were below threshold limit value-time-weighted average (TLW-TWA) except for two measures of dichloromethane and tetrachloroethylene, respectively, and in one measure of acetonitrile, which were higher then TLW-TWA. In exposed workers the prevalence of cough (p < 0.05) and nasal congestion at rhinoscopy (p = 0.05) was more frequent than in non-exposed workers. Occupational exposure (OR 4.5, 95% CI 1.2-16.5) and a low FEV1 (OR 2.6, 95% CI 1.1-6.3) were significant predictors of cough. CONCLUSIONS: In workers exposed to low levels of MDI and solvents in polyurethane shoe sole production there was a high prevalence of cough and nasal congestion. An improvement in the exhaust ventilation system and other preventive measures were needed.

Outcome of occupational asthma in patients with continuous exposure: a 3-year longitudinal study during pharmacologic treatment.

STUDY OBJECTIVE: To evaluate the effect of treatment with beclomethasone dipropionate (500 microg bid) and salmeterol (50 microg bid) on lung function and respiratory symptoms in 20 subjects with occupational asthma (OA) still exposed to the work environment cause of their disease. METHODS: At enrollment and every 6 months for 3 years, respiratory symptom score (from 0 [no symptoms] to 2 [moderate-to-severe symptoms]), spirometry, methacholine challenge, peak expiratory flow (PEF) variability, and the use of rescue salbutamol were evaluated. During the 3 years of follow-up, 10 subjects were excluded from the study because they retired or changed jobs. MEASUREMENTS AND RESULTS: Symptoms of work-related asthma started 12.6 +/- 13.1 years (mean +/- SD) before diagnosis. At baseline, mean FEV(1) was 80.2% of predicted values and provocative dose of methacholine causing a 20% fall in FEV(1) (PD(20)) was 1,001 +/- 1,275 microg; the workers received 2.1 +/- 2.4 puffs of salbutamol per day. After 3 years, no significant differences in any of the morbidity outcomes (FEV(1), PD(20), PEF variability, use of rescue salbutamol, respiratory symptom score) were found as compared with baseline or run-in values. CONCLUSIONS: Regular treatment with inhaled corticosteroids and long-acting bronchodilators seems to prevent respiratory deterioration over a 3-year period in workers with mild-to-moderate persistent OA who were still exposed at work to the environmental cause of their disease.

[Occupational asthma: role of airway inflammation and remodelling in persistent respiratory symptoms and bronchial hyper-responsiveness]. / Asma professionale: il ruolo dell'infiammazione e del rimodellamento delle vie aeree sulla persistenza dei sintomi e dell'iperresponsività bronchiale.

BACKGROUND: Until the late 1970's occupational asthma (OA) was considered reversible once patients were removed from exposure. Unfortunately, respiratory symptoms and non-specific bronchial hyper-responsiveness (NSBH) persist in about two-thirds of patients for years after removal from the offending agent. OBJECTIVES AND METHODS: This review focuses on the role of airways inflammation and remodelling in persistent respiratory symptoms and NSBH after cessation of occupational exposure. RESULTS: Even though cessation of exposure does not always result in remission of OA, symptoms, airways calibre and NSBH do improve in many patients. Although improvements in FEV1 and NSBH tend to reach a plateau 1-2 years after workers leave exposure, reversing NSBH may take much longer and respiratory symptoms and NSBH can persist in subjects removed from exposurefor >10 yrs. Long-term treatment with inhaled corticosteroids (ICS) induces a small but significant improvement in respiratory symptoms and in quality of life and a decrease in NSBH. Prolonged exposure and respiratory symptoms, marked airway obstruction and NSBH, high total cell, eosinophil and neutrophil counts in bronchoalveolar lavage fluid, a strong reaction during specific inhalation challenge, and delayed treatment with ICS have been identified as prognostic factors of unfavourable outcome. If exposure persists, OA tends to deteriorate in many patients but regular long-term treatment with ICS and long-acting beta2-agonists seems to stabilize the outcome. Soon after the last exposure inflammatory cell infiltrates, including eosinophils, and increased thickness of sub-epithelial collagen have been observed. When time since removal from exposure was longer, persistence of respiratory symptoms and NSBH was associated with airway inflammation, remodelling and hypersensitivity to the offending agent. Thickness of sub-epithelial collagen and specific airway sensitivity were reduced after prolonged non-exposure to isocyanates, although NSBH and airway inflammation persisted. CONCLUSIONS: Pathologic features are similar in OA and non-occupational asthma. The main factors of favourable outcome are early removal from exposure and a mild airway obstruction and NSBH at diagnosis. Persistence of airway inflammation years after removal from exposure suggests this process may become independent of the offending agent. The role of remodelling on persistence of OA needs to be clarified further.