Environmental Control and Trigger Management
Core concepts
Trigger management means matching an intervention to a documented exposure or sensitization: tobacco and other smoke, dust mites, cockroach and rodent allergen, molds and moisture, pets, pollen, outdoor ozone and PM2.5, cold air and exercise, occupational agents, and irritants such as fragrances, cleaning products, and VOCs. Also nitrogen dioxide from unvented gas stoves and wood smoke.
What the evidence supports
- Smoke-free home and car; cessation counseling at every visit; thirdhand smoke residue counts.
- Mite control: allergen-impermeable encasements on mattress, box spring, and pillows; wash bedding weekly in hot water; keep indoor humidity below 50%.
- Integrated pest management for cockroach and rodent: seal entry points, store food tightly, fix leaks, reduce clutter, use professional baiting rather than sprays.
- Mold: fix the water source; cleaning without moisture control fails.
The traps
Single-component interventions (a HEPA filter alone, an air cleaner alone) rarely improve outcomes; multifaceted, sensitization-targeted programs do. Allergen avoidance is indicated only when sensitization is documented, so mite covers for a non-sensitized patient are wasted effort. Exercise is not a trigger to avoid; pre-treat and warm up. Outdoor restriction should follow local air-quality alerts rather than fear of all outdoor activity.
Worked example
A child with positive mite and cockroach skin tests and nighttime symptoms: prioritize encasements, weekly hot-water bedding washing, humidity control, and pest management, not a bedroom air purifier.
Rule of thumb: no sensitization test, no targeted avoidance, but smoke-free housing advice applies to everyone.