A Closer Examination of
Dust MiteThe dust mite's mouth parts are grouped in front of body, resembling a head. Their body is oval and covered with fine striations. Their eight tiny legs have small sticky pads which enable them to burrow deep into carpet fibers and furniture, easily resisting pull of even most powerful vacuum cleaners. You definitely would not want to turn over in your bed and find yourself face to face with one of these strange looking creatures. Unfortunately, that is where their populations are often highest. The average bed can easily have over 10,000 dust mites living in it. Dust mites do not bite, sting or transmit diseases, so they pose no harm except to people who are allergic to a protein they produce. Their numbers have increased dramatically in past 20 to 30 years, especially during winter months, partly due to tighter homes where ventilation is limited and temperatures tend to be warmer.
Egg-laying female mites can increase population by 25 to 30 every three weeks. They go through five stages in their life cycle; from egg, larvae stage, then two nymphal stages, and finally adult. The adult may also molt once. This cycle from egg to adult takes about one month. Adult mites can live up to two months, depending on humidity levels and temperatures of their environment. They do not drink water but they absorb moisture from air and their environment. They just love higher relative humidities of 70-80% and temperatures of 75-80 degrees F in which their development and food consumption increases.
Dust Mites Produce a Powerful Allergen
It is protein DER p1 in faecal products and disintegrating body parts of these minute dust mites that has a mighty adverse effect on those who are allergic to it. Dust mites produce about 20 pellets per day, each measuring about 10 to 24 microns in size. To put that in perspective, diameter of human hair measures 80-100 microns. A gram of dust can hold 250,000 of these minute droppings. They are so tiny and light that they float easily into air when disturbed by our daily activities. Inhaling these minute particles causes allergic reactions in those who are sensitive to this protein.
Allergens from dust mite which cause asthmatic symptoms was first suggested in 1921 but analysis of dust did not happen until 1964 when a group led by Voohorst suggested that a mite may be responsible for dust allergen. It was soon established that dust mite droppings contain an allergen so they became a focus over years for their involvement with respiratory ailments. The DER p1 produced by dust mite is though to be most important allergen associated with asthma. About 10% of population are allergic to dust mite extracts.
Identifying Sensitivity to Dust Mite Protein
House dust contains many types of debris, including fabric fibers, human skin scales, human and animal dander, bacteria, cockroach parts, mold spores, food particles and other organic and synthetic materials. About 90% of people who are allergic to house dust extracts are allergic to dust mite extracts. Symptoms which may come from sensitivities to dust mite protein include sneezing, congestion, itchy, watery eyes and persistently stuffy nose and ears. Symptoms point more specifically to dust mites when you experience repeated sneezing shortly after awakening, symptoms get worse when beds are made or when using your vacuum cleaner, and improve when you are outside. Diagnosis, using scratch tests, etc., by an Allergist is recommended to determine which allergens cause reactions. These doctors who specialize in treating allergies can recommend a course of action specifically designed to reduce or eliminate your allergic reactions. This may include steps for reducing exposure to troublesome allergens, medical therapy and desensitization injections (Systemic Immunotherapy - SIT). The latter may be recommended if avoidance and medical therapy fail to sufficiently reduce allergic reaction. It involves injections of a dust mite extract starting weekly, followed by injections every six weeks for three to five years.
Importance of Reducing Exposure to Dust Mite Allergen
If your family is not sensitive to dust mite protein DER p1, managing them may not be a high priority. For those who suffer from it, management by reducing exposure to allergen DER p1 is quite important. Two important aspects which need to be addressed are removal of environments which are conducive to dust and dust mites and reduction of airborne dust mite droppings and disintegrating body parts. Inhaling these minute particles causes allergic reactions in those who are sensitive to this protein.
The exposure level at which you experience allergic reactions is determined by sum of exposure to all allergens you're sensitive to. Those who are sensitive to multiple allergens find that reduction of exposure to any of allergens will help in their tolerance of all allergens. It is important to realize that you do not need to completely eliminate exposure to allergens. Simply keeping your total exposure of all allergens below threshold at which you experience reactions is all that is necessary.
Reducing Exposure to Allergens in Your Bed
Due to amount of time we spend sleeping mattress should be covered with a protector, our bedrooms are areas which deserve most attention. Simply turning over in bed or breathing near your pillow can cause you to inhale minute dust mite droppings. Using hypo-allergenic fiberfill pillows is recommended over feather, kapok or foam since they are more easily washed. Encasing your pillows, mattress and box spring with plastic or specially coated or finely woven (pore size < 10 microns) vapor- permeable fabrics will deprive dust mites of food and prevent many of dust mite droppings from reaching you. The fabrics are more comfortable since they allow perspiration vapor to be more naturally carried away from your skin. Thorough vacuuming mattresses, especially seams and bed frame on a regular basis is also helpful. Wash your sheets and mattress pads in soapy water at 130 degrees F every one or two weeks to kill all mites. Bedding and curtains which can withstand frequent washing should be selected. Blankets can be dry cleaned or washed frequently. Using an electric blanket for eight hours every day can reduce dust mites in beds significantly. Heating blankets in a cloths dryer for several hours also kills mites. By doing this, dry cleaning or washing of blankets can be reduced to once a year.
