Diagnostics of Occupational Asthma: History and Exposure Investigations

1. Diagnostics of occupational asthma(history, exposure, allergologigal investigations, differential diagnostics) H. Keskinen MD Finnish Institute of Occupational Health

2. 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, diagnostics

3. 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 Occupational asthma, symptoms

4. Causes of cough/dyspnea • bronchial asthma • respiratory infections • COPD • hyperventilation • medication • reflux disease • cardiac causes • malignant disorders

5. 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/ history

6. exposure in own work exposure as bystander other work procedures in the same hall from the neighbouring hall non-occupational sensitizing agents pets hobbies Occupational asthma, exposure

7. patient occupational health services employer safety data sheets importer/manufacturer registers of occupational diseases literature Exposure, sources of data

8. flours enzymes storage mites spices egg milk powder sesame seed Bakery work, sensitizers

9. animal epithelia feed grains (rye, barley, wheat) storage mites natural rubber feed additives? (fish powder, enzymes, soya) Cattle breeding, sensitizers

10. diisocyanates (TDI, MDI, HDI) epoxy resins, organic acid anhydride or amine hardeners phthalates formaldehyde azodicarbonamide cyanoacrylates methacrylates polyfunctional aziridine hardener Manufacturing/use of plastic products, sensitizers

11. clinics natural rubber chloramine T glutaraldehyde formaldehyde animal epithelia (veterinary work) dental care natural rubber methacrylates chloramine T formaldehyde ammonium persulphate Health services, sensitizers

12. Persulphates Permanent wave chemicals Hair sprays Dyes Natural rubber Hair dressers, sensitizers

13. Soft soldering fumes (colophony) Diisocyanate cured varnishes Formaldehyde Epoxy resins, organic acid anhydrides Acrylate glues Electronics, sensitizers

14. Formaldehyde Diisocyanate cured paints Epoxypaints, amine hardeners Epoxy powder paints Polyester powder paints Paints with azidirine hardeners Painting, sensitizers

15. Formaldehyde (glues and shellacks) Wood dusts (exotic woods!) Diisocyanate hardened paints Aziridine hardened paints Moulds (mouldy wood dusts) Wood works, sensitizers

16. 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? Metal work, sensitizers

17. 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) Basic investigations

18. 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)

19. 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

20. 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

21. 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! Chemicals and specific IgE

22. 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, differential diagnostics

23. 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 Occupational asthma, diagnostics