II. Pathophysiology
- Sensitization to specific workplace chemical
- Initial response delayed from weeks to years
III. Causes: High Molecular Weight Substance Exposure (>1 kilodalton)
- Background
- Type I Hypersensitivity Reaction (IgE mediated)
- Symptoms within 20 minutes of exposure
- Resolves gradually within 1 to 2 hours
- Causes
- Flours or grain dust (Bakers, farmers, grain process)
- Insects (silk-processing, research)
- Seafood or marine organisms (seafood processors)
- Animal dander (animal handlers)
- Enzymes (Detergents, food industry, blood process)
- Gums or latex (manufacturing, health care)
IV. Causes: Low Molecular Weight Substance Exposure (<1 kilodalton)
- Background
- Allergic response of unclear mechanism
- Symptoms occur 3-4 hours after exposure
- Results in severe airway inflammation
- Causes
- Colophony: Abietic acid (electronic industry)
- Plicatic acid: Western red cedar dust (woodwork)
- Metals: Chromium, Platinum, Nickel (Refinery)
- Dyes (Textile industry)
- Persulfate salts, a bleaching agent (Hair dressing)
- Anhydrides: Trimellitic, Phthalic (Plastics)
- Acrylates such as Methacrylate (Adhesive workers)
- Glutaraldehyde or Formaldehyde (Health care)
- Pharmaceuticals (Pharmaceutical Industry)
- Polyurethane (paints and adhesives)
- Diisocyanate: Toluene, Diphenylmethane, Hexamethylene
- Used in plastic and Rubber
- Used to create foam insulation
- Used to harden polyurethan paints (auto, boat)
V. Differential Diagnosis
-
Intrinsic Asthma
- Nonspecific triggers for airway hyperresponsiveness
-
Reactive Airway Dysfunction Syndrome
- Follows very high irritant exposure