House dust mite allergy

What is the house dust mite (HDM)?

The house dust mite is a tiny creature that is present in every home. The tiny droppings (faeces) of the house dust mite are the main triggers for an allergic reaction. HDM lives off the human skin scales, and thrives on a warm and humid environment. It is thus found abundantly in our bed linen, mattresses, pillows, carpets, and upholstered fabric.

 

What are the typical symptoms of HDM allergy?

The typical symptoms are:

•Itchy, runny or blocked nose.

•Sneezing.

•Coughing, wheezing, shortness of breath.

•Itching & watering of eyes.

•Itchy skin, rashes, & wheals.

•Congested sinuses and headache.

•Symptoms tend to be worse indoors, in bed or early morning.

Not uncommonly patients note that their symptoms improved when they go abroad to a hot or dry climate.

How do I know if I have house dust Mite allergy?

Patients with all or some of the above symptoms should consult their doctor. After taking a history and examining the inside of your nose to exclude other causes that may be giving rise to your symptoms, he or she may request that you have a test (skin prick test or a blood test) to ascertain whether you are allergic to house dust mite. and other common specific allergens. The test will confirm the diagnosis.

What is the treatment for house dust Mite allergy?

The treatment options are:

1.Allergen avoidance

2.Medical therapy

3.Surgical therapy

Allergen avoidance

Complete allergen avoidance would be the ultimate treatment, but it is not possible to keep one’s home permanently clear of the mite. However, the following measures will help greatly reduce their number, and thus may help with symptom control. Most efforts at controlling dust mites should be aimed at areas of the home where you spend most of your time and where dust mite load is greatest, i.e. bedrooms and living areas

•Fit dust proof covers to mattresses, pillows and duvets.

•The usual covers can be put on top of the dust proof covers, but should be hot-washed every week at 60 degrees centigrade.

•Use feather rather than synthetic pillows.

•Keep carpets, soft furnishings and toys to a minimum in the bedroom.

•The bedroom should be regularly ventilated, vacuumed regularly with a high filtration vacuum cleaner, and its furniture should be cleaned with a damp cloth weekly.

•Use light washable cotton curtains, and wash them regularly.

•Hot Wash (60 degrees centigrade) stuffed toys frequently, alternatively put them in the freezer in a plastic bag for 12 hours once a month.

•Reduce humidity by increasing ventilation (by opening windows, using extractor fans etc) or by using a dehumidifier (keep humidity below 50%, but above 30%).

•Vacuum upholstered furniture twice a week with high filtration vacuum cleaner & damp wipe all surfaces twice a week.

•Reduce unnecessary soft furnishings

Medical Therapy

Medical therapy is usually most effective if combined with measures described above to minimise allergen avoidance. Treatment involves:

•Antihistamine tablets regularly, or when symptoms are particularly troublesome.

•Symptomatic control with nose sprays, or eye drops.

Surgical therapy

On occasions when the nasal blockage is chronic and does not respond to regular use of nasal sprays then limited benefit may be gained from surgery. Surgery involves cautery to the lining of the part of the nose (inferior turbinates), which typically are the principal areas that are most congested. This is a day case procedure, and initially the nose will feel more congested following surgery. After this initial period patients often report a significant improvement in their symptoms. However, in most people this effect is often not permanent.

Further information may be obtained from:

Allergy UK No 3 White Oak Square, London Road, Swanley, Kent, BR8 7AG

Tel: 01322 619898 Allergy Help Line: 01322 619864 www.allergyuk.org