Occupational asthma - Sotsiaalministeerium
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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
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
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
exposure in own work
exposure as bystander
– other work procedures in the same hall
– from the neighbouring hall
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
Health services, sensitizers
clinics
– natural rubber
– chloramine T
– glutaraldehyde
– formaldehyde
– animal epithelia (veterinary
work)
dental care
– natural rubber
– methacrylates
– chloramine T
– formaldehyde
– ammonium persulphate
Hair dressers, sensitizers
Persulphates
Permanent wave chemicals
Hair sprays
Dyes
Natural rubber
Electronics, sensitizers
Soft soldering fumes (colophony)
Diisocyanate cured varnishes
Formaldehyde
Epoxy resins, organic acid anhydrides
Acrylate glues
Painting, sensitizers
Formaldehyde
Diisocyanate cured paints
Epoxypaints, amine hardeners
Epoxy powder paints
Polyester powder paints
Paints with azidirine hardeners
Wood works, sensitizers
Formaldehyde (glues and shellacks)
Wood dusts (exotic woods!)
Diisocyanate hardened paints
Aziridine hardened paints
Moulds (mouldy wood dusts)
Metal work, sensitizers
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
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
Skin prick tests (SPT)
– common environmental allergenes
(pollen of trees/grasses, animal epithelia, house
dust mites, moulds, natural rubber)
– commercial extracts (ALK Abello, Denmark)
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
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
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
Note:
– extracts of work-related sensitizers not
standardized, wrong negative/positive tests?!
– only IgE-mediated allergies are found
Chemicals and specific IgE
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
Non-occupational allergies
– e.g. pollen, pets
– constant asthma symptoms, irritants at work cause increasing
symptoms
Intrinsic-type asthma
– all irritants and strain, also at work, increase symptoms
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