Transcript Occupational asthma - Sotsiaalministeerium

Diagnostics of occupational asthma
(history, exposure, allergologigal investigations, differential
diagnostics)
H. Keskinen MD
Finnish Institute of Occupational Health
Occupational asthma,
diagnostics
 work-related
asthmatic
symptoms
 exposure to a sensitizing agent at
work
 cause-effect relationship between
the exposure and asthma
– sensitization (skin prick tests / specific IgE
antibodies)
– typical long-term PEF surveillance
– positive provocation tests
Occupational asthma, symptoms
Cough, production of mucus, dyspnea
 related to work
– during working hours
– in the evening after the work day
– during the night after work days
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no symptoms during days off
later symptoms also during weekends, but
improving when away from work for
longer periods
Causes of cough/dyspnea
 bronchial asthma
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respiratory infections
COPD
hyperventilation
medication
reflux disease
cardiac causes
malignant disorders
Occupational asthma/ history
 What
is your work? (ask every patient with
cough/dyspnea!)
 What
are the symptoms?
 When did they begin?
 How are they related to work?
 Specific agents ? old? new?
 Change in working habits?
 Change in the work environment?
 Symptoms of respiratory infection?
 Smoking?
Occupational asthma, exposure
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exposure in own work
exposure as bystander
– other work procedures in the same hall
– from the neighbouring hall
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non-occupational sensitizing agents
– pets
– hobbies
Exposure, sources of data
 patient
 occupational
health services
 employer
 safety
data sheets
 importer/manufacturer
 registers of occupational diseases
 literature
Bakery work, sensitizers
 flours
 enzymes
 storage
mites
 spices
 egg
 milk
powder
 sesame seed
Cattle breeding, sensitizers
 animal
epithelia
 feed grains (rye, barley,
wheat)
 storage mites
 natural rubber
 feed additives? (fish powder,
enzymes, soya)
Manufacturing/use of plastic
products, sensitizers
diisocyanates (TDI, MDI, HDI)
 epoxy resins, organic acid anhydride or
amine hardeners
 phthalates
 formaldehyde
 azodicarbonamide
 cyanoacrylates
 methacrylates
 polyfunctional aziridine hardener
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Health services, sensitizers
 clinics
– natural rubber
– chloramine T
– glutaraldehyde
– formaldehyde
– animal epithelia (veterinary
work)
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dental care
– natural rubber
– methacrylates
– chloramine T
– formaldehyde
– ammonium persulphate
Hair dressers, sensitizers
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Persulphates
Permanent wave chemicals
Hair sprays
Dyes
Natural rubber
Electronics, sensitizers
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Soft soldering fumes (colophony)
Diisocyanate cured varnishes
Formaldehyde
Epoxy resins, organic acid anhydrides
Acrylate glues
Painting, sensitizers
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Formaldehyde
Diisocyanate cured paints
Epoxypaints, amine hardeners
Epoxy powder paints
Polyester powder paints
Paints with azidirine hardeners
Wood works, sensitizers
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Formaldehyde (glues and shellacks)
Wood dusts (exotic woods!)
Diisocyanate hardened paints
Aziridine hardened paints
Moulds (mouldy wood dusts)
Metal work, sensitizers
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Welding fumes (MMA) and grinding dusts of
stainless steel
Hard metal dust
Welding fumes of painted steel (2-component
paints)
Aerosols of cutting fluids
Other welding fumes?
Basic investigations
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physical status, lung auscultation
chest X-ray (also nasal sinuses if needed)
blood sedimentation rate, CRP, blood count,
eosinophils
spirometry, also after bronchodilating medicine
histamine/metacholine challenge
exercise test (EKG, FEV1, blood gases), if needed
diffusion capacity, if needed
total IgE
skin prick tests (common environmental allergens)
Investigations of allergy/environmental
allergens
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Skin prick tests (SPT)
– common environmental allergenes
(pollen of trees/grasses, animal epithelia, house
dust mites, moulds, natural rubber)
– commercial extracts (ALK Abello, Denmark)
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Total IgE
Determination of specific IgE
– if skin prick test not possible
– specific allergens, not available as SPT
– commercial tests (Pharmacia, Sweden)
Skin prick tests, sensitizing agents at work
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Skin prick tests
– commercial extracts (ALK Abello, Denmark)
e.g.: flours, animal epithelia, moulds, storage
mites, natural rubber
(chemicals not commercially available as SPT!)
– "in-house" extracts (quality? testing of control
persons!)
 freeze-dried allergens
 chemicals, conjugated with HSA
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Note: - extracts of work-related sensitizers not
standardized,
wrong negative/positive tests?!
- only IgE-mediated allergies are found
Determination of specific IgE, sensitizing
agents at work
– commercial tests (Pharmacia, Sweden)
(flours, animal epithelia, moulds, storage mites,
natural rubber, chloramineT, diisocyanates, acid
anhydrides, formaldehyde)
– "tailor made" tests
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Note:
– extracts of work-related sensitizers not
standardized, wrong negative/positive tests?!
– only IgE-mediated allergies are found
Chemicals and specific IgE
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Asthma due to diisocyanates - only about 20% of the
diagnosed cases have been IgE-mediated (RAST +:ve)
Asthma due to organic acid anhydrides - most often
RAST +:ve
Occupational asthma due to formaldedyde - rarely
RAST +:ve
Negative RAST does not exclude occupational
asthma!
Occupational asthma, differential
diagnostics
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Non-occupational allergies
– e.g. pollen, pets
– constant asthma symptoms, irritants at work cause increasing
symptoms
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Intrinsic-type asthma
– all irritants and strain, also at work, increase symptoms
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COPD
– marked obstruction, strain and irritants increase symptoms
Occupational asthma,
diagnostics
 history
– work-related asthmatic symptoms
– exposure to a sensitizing agent at work
 clinical
investigations for
verifying the cause-effect
– sensitization to agents at work
– cause-effect relationship between the
exposure and astma of the patient