mathias holm, m. d., phd occupational and environmental medicine (arbets- och miljömedicin)
DESCRIPTION
Asthma, allergy and laboratory work. Mathias Holm, M. D., PhD Occupational and Environmental Medicine (Arbets- och miljömedicin) Sahlgrenska academy and University Hospital 2013-03-21. Inflammation – allergic or non-allergic. Mucous membranes Eyesitching, red, edema, secretion - PowerPoint PPT PresentationTRANSCRIPT
Mathias Holm, M. D., PhD
Occupational and Environmental Medicine (Arbets- och miljömedicin)
Sahlgrenska academy and University Hospital
2013-03-21
Asthma, allergy and laboratory work
Inflammation – allergic or non-allergic
Mucous membranes
– Eyes itching, red, edema, secretion
– Nose edema, secretion, sneezing
– Airways edema, secretion, constriction (asthma)
Skin eczema, nettle rash
Allergy
Reaction in the immune system.
Specificity, “memory”, host factors of importance.
Reactions in mucous membranes mediated by immunoglobuline E (IgE, type I).
Eczema by cells (type IV), nettle rash by IgE.
Non-allergic reactions
Hypersensitivity
Other specific immunologic mechanism (not type I or IV)?
Other, non-immunologic mechanism??
Irritation
Non-specific mechanism
– No specificity, no memory?
– Host factors important, variable sensitivity
Corrosion
Very strong irritation, irreversible tissue damage.
Allergen in IgE-mediated reactions
High molecular allergen Low molecular
Often protein mw 5-100 kD chemical
Hapten
Human protein
What causes allergy?
IgE-mediated reactions
High molecular agents
– Pollen, furred animals, mites
– Plants, fish and shellfish, enzymes, latex, lab animals, insects
Low molecular agents (also other mechanisms)
– Diisocyanats, acid-anhydrids, cyanoacrylate, some amines, glutaraldehyde, persulfates
High molecular agents can cause asthma, rhinitis
IgE- mediated reactions
Skin prick test
Low molecular agents can cause asthma, rhinitis
Symptoms from airways by irritants - vapour, gas, dust, fumes
Irritation/corrosion on skin and eyes and airway irritation
Irritation and corrosion - localised effects at the place of contact between the agent and the skin, eyes or airway mucous membrane.
Corrosive substances may destroy tissues at first contact.
Irritating substances are non-corrosive substances that may cause inflammation in tissues at first contact.
Irritating chemicals - irritation in airways.
Irritation – reversible changes (usually – obs! asthma).
Also toxic effects (interaction with autonomic nervous system) leading to reflexes (sneezes, cough, etc). These effects are reversible.
Irritation/corrosion on skin and eyes and airway irritation
Allergic contact eczema
Delayed, cell mediated reaction
–Nickel, chrome, cobalt
–Rubber chemicals
–Pharmaceutical drugs, cosmetics (Kathon)
–Colophony, perfume, plants
–“Chemicals” R-phrase 43
Epoxy, acrylates, resins, plastic chemicals, organic dyes, amines etc.
Patch test
Irritative eczema
Trigger factors
Chemical irritation
Mechanical irritation
Heat, perspiration
“Dry skin”
Infection?
Stress
Climate factors (e g time of year)
Accident with 4 liters acetic acid in room ca 12 m2
Asthma after accident
Exposure Fraction with asthma
Percent with asthma
Low 0/6 0
Mean 4/21 19
High 4/9 44
Follow up of 51 persons, 36 previously without airway disease, exposure was estimated.
Substance CAS-nr Year Occupationalexposure limit (8 hour)
Occupationalexposure limit(15 min)
ppm mg/m3 ppm mg/m3
Acetic acid 64-19-7 1990 5 20 10 25
Extract from CLP-regulation
H332 Harmful if inhaled (skadligt vid inandning)
H334 May cause allergy or asthma symptoms or breathing difficulties if inhaled (kan orsaka allergi- eller astmasymtom eller andningssvårigheter vid inandning)
H335 May cause respiratory irritation (kan orsaka irritation i luftvägarna)
HarmfulAcut toxicity (oral, dermal, inhalation)Skin irritationEye irritationSkin sensitisationSpecific organ toxicity – single exposureAirway irritationNarcotic effects
Product is harmful by inhalation, skin contact or ingestion. Also used for products causing allergy at skin contact, irritating skin, eyes or airways or having narcotic effects.
Health hazardRespiratory sensitisation Germ cell mutagenicity CarcinogenicityReproductive toxicitySpecific Target Organ Toxicity — Single exposure, Specific Target Organ Toxicity — Repeated exposure Aspiration hazard
Product may cause hereditary genetic damage, cancer, be teratogenic or impair reproduction. Also used for products causing allergy when inhaled, chemical pneumonitis at ingestion or other serious damages at single or repeated exposure.