House Dust Mites

Overview:

Also known as dust mites or HDM, dust mites are eight legged, microscopic arthropods, closely related to spiders and ticks. Dust mites feed on shed skin cells & thrive in warm & humid environments. They live in areas with high concentrations of shed skin such dust (hence the name),  carpets, mattresses,  pillows, curtains, stuffed toys, other soft furnishings & carpet.  

Proteins in their feces are a common cause of asthma & allergies in humans. Allergies occur when the body is exposed to an allergen and the immune system reacts inappropriately. Most harmless allergens are ignored by the body, but in some individuals, their immune system interprets the allergen as harmful. This causes the production of antibodies known as IgE to the particular allergen (pollen, dust mite feces, cat dander etc). IgE trigger cells known as mast cells to  release histamine, it is histamine that causes allergy type symptoms such as inflammation, runny nose etc.

Symptoms of house dust mite allergy:

Common symptoms of dust mite allergy include typical allergy type symptoms such as;

• Wheezing
• Runny nose
• Sneezing
• Nasal congestion
• Cough
• Itchy/watery eyes
• Asthma/difficulty breathing
• Atopic dermatitis (eczema)

Diagnosis of house dust mite allergy:

Your doctor will perform a medical examination & obtain a history from you. This will include questions such as symptoms you are experiencing, when they occur (day, night, all the time), if they are seasonal (worse in spring etc).

Tests your doctor may wish to perform include;

• Skin allergy test

• Blood test

• Lung function

Treatment for dust mite allergies:

• Antihistamines – These block the effects of histamine.
• Asthma medication – These come in two forms. Relievers & preventers.
• Immunotherapy - This involves a series of shots that can help increase your tolerance to dust mites.
• Nasal sprays
• Decongestants

House dust mite control:

You can’t completely eliminate dust mites from the environment but there are steps you can take to reduce the numbers. These include;

• Reduce carpeting in the home. Replace with hardwood flooring, linoleum or tile.
• Reduce the amount of soft furnishings in the home.
• Regularly wash all bedding in the hottest water possible. Bedding, pillows, sheets, curtains, washable soft toys, cushion covers etc.
• Any soft toys that can’t be washed can be placed in the freezer overnight. This obviously won’t eliminate the droppings, but it will kill the house dust mites.
• Replace feather pillows with synthetic ones.
• Where possible, dry clean soft furnishings such as curtains.
• Cover your mattress with a washable, dust proof cover. Better still, use mite proof covers.
• Dust your home regularly (ie; every few days).
• Dehumidifying your home. Aim to keep humidity below 50%.
• Regularly place rugs outside in direct sunlight. This will kill the mites, but won’t remove the allergen. Regular vacuuming can help remove mite droppings from rugs.
• Regularly vacuum. The best type of vacuum cleaners have a HEPA filter. This includes vacuuming the mattress, paying particular attention along the seams.
• Wrap out of season clothing in plastic. Store in a dry location.