Asthma and rhinitis in wooding workers

We present some cases of rhinitis and asthma in wooding workers exposed to hard or soft woods. The specific provocation test confirmed the diagnosis of rhinitis in three patients and of asthma in four. Rhinitis was caused by oak, beech, and pine, while asthma was caused by obeche, chestnut, acacia, and iroko. Occupational exposure to the specific wood, before onset of symptoms (symptom latency) was shorter for patients with asthma. All seven patients with respiratory symptoms were nonsmokers; three were atopics and four, all with asthma, had nonspecific bronchial hyperreactivity. Twenty-four hours after the test, PD20FEV1 had decreased in two cases with rhinitis and two with asthma, although the data did not reach statistical significance (Wilcoxon matched-pairs test: NS). After the SBPT, blood eosinophils increased in two cases with rhinitis and three with asthma, and the data were at the limit of statistical significance (P = 0.046). The study confirms that not only hard essences, but also soft woods can cause respiratory symptoms, although the pathogenetic mechanisms are still unclear. A specific provocation test is still the best and sometimes only means of diagnosing wood asthma; standardized protocols with repeated measurements of nonspecific airway responsiveness and of eosinophils in the blood may be helpful for a better understanding of the pathogenetic mechanism and predisposing factors.