Symptoms that indicate dust mite exposure are sneezing, watery and itchy eyes, nasal stuffiness, a runny nose and stuffy ears. Additional symptoms include eczema, respiratory problems, bites and in severe cases, asthma.
Approximately 10 percent of Americans exhibit allergic reactions to dust mites, according to the American College of Asthma, Allergy and Immunology. The fecal pellets and body fragments are the primary cause of allergic response. Dust mites may be invisible but still cause a person to experience physical symptoms such as hay fever, postnasal drip, cough and facial pressure and pain.
Proteins in dust mite feces produce antibodies in people who are allergic. When the feces touch the skin or are inhaled, the antibodies cause the release of histamines which result in nasal swelling and congestion. These symptoms may be aggravated during the fall and winter months when windows and doors are closed and there are greater concentrations of dust mites indoors. Symptoms may also worsen in rooms with poor ventilation, high humidity and temperatures over 70 degrees.
Dust mites dwell in bedrooms where people spend a large portion of their time and shed skin. The bed itself is a prime habitat, as they prefer warm, moist surroundings such as the inside of a mattress. They are extremely small, usually less than a millimeter long, and often not visible to the naked eye. They feed off dead skin, hair and dandruff.