Early incidence of occupational asthma is not accelerated by atopy in the bakery/pastry and hairdressing sectors.

Setting: Occupational asthma (OA) is most likely to develop in the very early years of exposure.

Objective: To describe the early incidence of OA among bakers/pastry-makers (BP) and hairdressers and to explore the role of atopy.

Design: Following a retrospective follow-up design, subjects were invited to undergo telephone interviews. Those who declared work-related respiratory or rhinitis symptoms and a sample group of others were offered a medical visit for OA investigations. Data from interviews and from medical visits were used to estimate the incidence of OA according to increasing durations of exposure.

Results: A total of 866 subjects were interviewed (mean age 25.3 years, 43.8% females), of whom 282 underwent a medical visit. Total estimated incidence rates of 'confirmed or probable' OA during the first 12 years of exposure were high in BP (2.63 per 100 person-years [py]) and in hairdressers (0.58/100 py), particularly in the first 4 years. Atopy is a strong risk factor for incidence among BP but, irrespective of the occupational sector, it does not influence the timing of OA symptoms.

Conclusion: OA symptoms occur soon after the start of exposure. Our results suggest that atopy does not precipitate the occurrence of symptoms in two different allergen exposure settings.