ALLERGEN- is any substance that can causean allergy.- In technical terms, an allergen isan antigen capable of stimulatinga type-I hypersensitivity reaction inatopic individualsthrough Immunoglobulin E (IgE)responses. Sensitivities vary widely fromone person to another.
AEROALLERGENS (aer·o·al·ler·gen) - any airborne substance which triggers an allergic reaction.
Classified into three groups:• pollen (tree, weed, andgrass),• mold, and• indoor allergens.
POLLENS - a fine powdery substanceproduced by the anthers of seed-bearing plants. Aeroallergens include the pollensof specific seasonal plants causingallergy commonly known as hay fever.
Examples of plant pollen commonlyresponsible for hay fever include:Trees:such asbirch, alder, cedar, hazel, hornbeam, horsechestnut, willow and olive.
Grasses:especially ryegrassand timothy . *An estimated90% of hay feversufferers areallergic to grasspollen.
Weeds:ragweed, plantain, nettle, mugwort, and sorrel.
Electron microscope image of pollen grains from a variety of common plants: sunflower, morning glory, prairiehollyhock, oriental lily, evening primrose, and castor bean.
• Tip of a tulip stamen • Close up image of awith many grains of cactus flower and itspollen stamens
In fungi, spores ofmany fungal species areactively dispersed byforcible ejection fromtheir reproductivestructures, which travelthrough the air overlong distances.
INDOOR ALLERGENS Dust mite debris is the majorsource of allergens in house dust. These microscopic arthropodsprimarily feed on human skinscales.
- these animals aremajor contributorsto indoor allergenexposure.
Felis domesticus, the major catallergen, is produced primarily inthe sebaceous glands and issecreted onto the skin and fur. Thisallergen is also present in thesalivary glands. The allergen is chiefly carried onsmall particles and remains airbornefor long periods.
COCKROACH Cockroachallergens are derivedfrom saliva, fecalmaterial, secretions,and dead bodies ofcockroaches.
Aeroallergens and Climate Change Changes in climate could impactthe production, distribution, anddispersion of aeroallergens; allergencontent; and the growth anddistribution of theweeds, grasses, tress, and mold thatproduce them.
1. Aeroallergen Production CO2 concentration - acts as a fertilizer for plant growth, thus increasing pollen production and the allergen content of pollen grains. precipitation and temperature - also led to enhanced pollen production.
2.Timing of Aeroallergen Production Higher temperatures and humidity - changing the timing and duration of the pollen season. Phenologic advance is likely to occur for numerous species of plants, especially trees.
3. Distribution and Dispersion ofAeroallergens There will likely be changes in the distribution of pollen producing species, including the possibility of extinction in some cases. Intercontinental dispersal is possible, facilitating the introduction of new aeroallergens into other areas.
4. Allergenic Content of Aeroallergensinfluence of meteorological variables, such as temperature and precipitation, and air pollutants, such as CO2, on the concentration of allergen protein of pollen.
Prevention/Adaptation Zero Order Prevention: Decrease emissions of and/or increase sinks for greenhouse gases enhancing greenhouse gas sinks and decreasing greenhouse gas emissions that lead to global warming. decrease carbon footprints and encourage others to do the same
Primary Prevention: Reduce exposures to aeroallergens Monitor aeroallergen and ozone alert forecasts and minimize exposures Use of HEPA filters should be encouraged for asthmatics to decrease penetration of aeroallergens into the home Advise asthmatic patients to avoid overexertion and/or excessive time outdoors during days of high pollen counts and air pollution Create and implement education programs about the importance of allergen avoidance for allergy sufferers, particularly asthmatics Design and protect landscapes that produce lower levels of aeroallergens within the context of local ecology
Secondary Prevention: Prevent onset of allergic illnesses Use allergy and asthma medications as prescribed Check pollen forecasts and avoid excessive time outdoors on high pollen days Advise patients on the correct ways to prevent onset of allergies through medications Communicate the importance of limiting exposure on high pollutant days
Tertiary Prevention: Treat allergic illnesses Seek medical help if necessary Ensure medications are widely available
Fungi Reduce spore infiltration - windows and doors should be kept closed as much as possible. Moisture control - Repair leaks, use air conditioning at times of high humidity, ventilate bathrooms and kitchens, and heat all rooms in the winter. Cleaning - use detergent solution with 5% bleach Air filters - HEPA filters Masks - a pollen mask is useful during activities such as cleaning and vacuuming
Dust mites Impermeable covers -composed of either vinyl or tightly woven fabric and serve as effective dust mite barriers. Elimination of dust reservoirs -remove stuffed toys, books, or other items that collect dust, particularly in the bedroom. Vacuuming - Weekly vacuuming is recommended, and vacuum bags should have 2 layers or a HEPA filter to decrease aerosolized allergen exposure because of the air disturbance.
Washing - Washing linens in hot water (55°C [131°F]) at least weekly is recommended to kill the mites and remove most of the associated allergen. Air purifiers Freezing - Dust mites die when frozen; therefore, stuffed toys and other such items can be placed in a domestic freezer to decrease dust reservoirs. Acaricides - Disodium octaborate tetrahydrate (DOT) is safe for humans and effectively kills mites. Relocation - high altitudes or arid locales are associated with less mite growth.
Cats and Dogs Removal of the pet or Restrict pet access - pet should be kept outdoors. Washing the pet - wash the pet at least twice weekly. Air purifiers
Cockroaches Pesticides - Pesticide spray is effective, but selective placement of gels or baits is preferred. Cleaning Elimination of food and water supply - Food should be stored in sealed containers, and any sources of standing water should be removed.