Occupational allergy and asthma in bell pepper horticulture: natural course

The prevalence of occupational allergy and asthma has increased over the past
few decades. Nearly 10% of all adult-onset asthma can be attributed to the work
place. Workrelated symptoms are also often mentioned by workers in the bell
pepper horticulture. A cross-sectional study on the prevalence of occupational
allergy in bell pepper horticulture was performed in 1999 en 2000. This study
demonstrated workrelated symptoms in 53.8% and sensitisation to the bell pepper
plant in 35% of the workers (472). The bell pepper cultivation with a current
workforce of 5000-7000 has increased during the past few years. In the current
situation preliminary detection of workers at risk of developing sensitisation
or disease is not yet possible. To identify employees at risk at an early stage
more knowlegde is required about the natural course of occupational allergy and
the risk factors. The size of work force (nowadays 5000 -7000 employees) in the
bell pepper horticulture and the extraordinary high rate of reported symptoms
and sensitisation to occupational allergens emphasises the importance of the
project for this branch of agricultural industry. Although bell pepper
employees only are subject of study, this branch of industry may serve as a
model for many other kinds of horticulture characterised by pollen exposure.

In this investigation the natural course of occupational allergy and asthma in
bell pepper greenhouses is studied and the determinants of the development of
sensitization and symptoms in the cohort of 472 employees, studied in 1999 are
assessed. With these data we will develop separate models to identify
prognostic factors for development of sensitisation, occupational rhinitis and
asthma respectively. This way, workers at risk of developing sensitisation and
disease can be identified at an early stage, while preliminary detection in the
current situation is not yet possible. The prediction models may tailor the
treatment to the nature and severity of symptoms and prioritise the
intervention according to the expected effects on daily functioning.
Also, the burden of disease will be determined in terms of medical consumption,
labor force participation, work productivity. From this analysis direct and
indirect costs can be calculated.

Bell pepper emplyees who participated in a cross-sectional survey in 1999 will
be approached and will be asked to participate in a second survey. Subjects
lost to follow up will be traced and asked to participate. Biographic data,
data concerning respiratory symptoms, data on job characteristics, on medical
consumption, on productivity at work and on sickness absence and
rhinitis/asthma quality of life questionnaires will be gathered. Also a skin
prick test with allergen extracts will be performed including bell pepper
pollen, thyrophagus, botrytis, amblyseius cucumeris and common inhalant
allergens.

A systemic adverse reaction after a skin prick test (an allergic reaction to
the skin test) is rare, because only a minimal amount of allergen is used.
Local itchiness can occur. Apart from the direct skin reaction (after 15
minutes) an itchy swelling can appear after 6 hours. This swelling will
disappear in the next few days.
The duration of the visit amounts approximately one hour.