Advise about House dust
House dust is the major cause of allergy in persons with year-round complaints of runny or stuffy nose, itchy, watery eyes and sneezing. In addition to these allergic reactions, dust can trigger asthma attacks of wheezing, coughing and shortness of breath

What’s in house dust that causes allergies?
House dust is a conglomeration of debris of many sorts. The content varies from home to home, depending on furnishings, pets, building materials and location. A speck of dust may contain fabric fibres, human skin scales, animal danders, bacteria, cockroach parts, mould spores, food particles or other organic and synthetic materials. A person may be allergic to one or more of these substances especially cat or dog danders.
However, of all the many components of house dust, a microscopic creature called he house dust mite causes most of the trouble. These mites feed on skin scales and danders shed by humans, and appear to be the major allergen (allergy causing substance) in house dust. A study in England showed that 10% of the population and 90% of allergic asthmatics have positive skin tests to mites. Recent studies in the U.S. suggest that at least 45% of young asthmatics are allergic to mites.

Is dust allergy a sign of a dirty house?
No. Certainly a dirty house can worsen the problem and it’s important not to let surface dust accumulate, but more-than-ordinary housekeeping measures may be needed to help relieve house-dust allergy. The task of getting rid of dust is complicated by the fact that usual cleaning methods e.g. vacuuming, dusting, and sweeping actually raise dust levels in the air. Even thoroughly vacuuming and dusting do not reduce the number of mites growing in carpeting or mattresses.

What are dust mites like?
Mites are members of the eight legged- Arachnid family and are distantly related to spiders, fleas and ticks. Like the germs on your door knob, they can’t be seen without a microscope. They thrive in warm, humid conditions. They’re hardy, surviving and multiplying best when the relative humidity is at 75-80% and the temperatures is around 25 degrees. Mites cannot survive when humidity falls below 40-50%. They are very rare in dry, high altitude areas.
Because they feed on skin scales, they love bedding, carpeting, Upholstered furniture, clothing, cupboards and car upholstery. They survive vacuuming because they burrow deep in carpet fibres and are equipped with sucking sticking pads on the ends of their legs. They don’t bite of transmit diseases – they are harmful only to people who become allergic to them.
People become allergic to proteins in mites and mite faeces. The faecal pellets are so tiny and light that they float easily into the air when carpet is walked upon or bedding is shaken, or when the vacuum cleaner is run. When floating pellets are inhaled by a sensitive person, allergic symptoms result.