Health and Medicine

Diseases, Disorders, and Other Health Problems

What are dust mites?

Dust mites are microscopic arachnids (members of the spider family) commonly found in house dust. Dust mite allergen is probably one of the most important causes of asthma (breathlessness and wheezing caused by the narrowing of small airways of the lungs) in North America, as well as the major cause of common allergies (exaggerated reactions of the immune system to exposure of offending agents).

Thorough, regular cleaning of the home, including the following measures, will help control dust mites:

  1. Clean all major appliances such as furnaces and air conditioners, and change filters as recommended by the manufacturer.
  2. Launder bedding every seven to ten days in hot water. Use synthetic or foam rubber mattress pads and pillows. Cover mattresses with dust-proof covers. Clean or replace pillows regularly.
  3. Keep moist surfaces in kitchen and bathroom clean and free of mold.
  4. Vacuum and dust often. A high-efficiency particulate air filter (HEPA) vacuum is especially effective.

If the sap of the poison ivy plant touches the skin, will a rash develop?

Studies show that 85 percent of the population will develop an allergic reaction if exposed to poison ivy, but this sensitivity varies with each individual according to circumstance, age, genetics, and previous exposure. The poison comes mainly from the leaves whose allergens touch the skin. A red rash with itching and burning will develop, and skin blisters will usually develop within six hours to several days after exposure. Washing the affected area thoroughly with mild soap within five minutes of exposure can be effective; sponging with alcohol and applying a soothing and drying lotion, such as calamine lotion, is the prescribed treatment for light cases. If the affected area is large, fever, headache, and generalized body weakness may develop. For severe reactions, a physician should be consulted to prescribe a corticosteroid drug. Clothing that touched the plants should also be washed.


This is a web preview of the "The Handy Science Answer Book" app. Many features only work on your mobile device. If you like what you see, we hope you will consider buying. Get the App