Why study the mite

Allergy is fast becoming an epidemic in the developed world and house dust mites are recognised as a major cause of allergy.

Up to one in three children in Europe suffers from allergy, and overall 35% of the population is affected. Westernised populations born after the 1980 will perceive allergic eczema and the accompanying atopic state as a major public health problem. Allergic diseases vary in different countries and within countries it may vary between regions. Social environments, climate and life style all may have an effect on the outcome of a genetic predisposition to allergy. Most allergic diseases are chronic and relapsing, 10% of patients, diagnosed as severe and chronic, account for 60% of the total health cost. It is in the public interest to identify these people early and control the potential march of allergic disease.

From early studies on large populations born in the1950s scientists have been able to observe the march of allergy in western society. They have identified a vulnerable group of people along with major environmental risk factors that impact negatively upon their health. The scientists are working on the genetic ‘fingerprinting’ of these people to identify methods to reduce the risks from allergic disease. They have clearly warned us that there is no easy pathway. Help will come in the form of an educated public choosing a selected diet and life style combined with avoiding known environmental and stress related risk factors.

Established allergies may be able to attack one or more organs in allergic disease. Most noticeable and common are lungs (asthma) nasal passages (rhinitis) eyes (conjunctivitis) and skin (eczema). In severe and chronic allergic disease, one, two or maybe all may be present and lead to a reduction of the patient’s quality of life.

COMMON CAUSES OF ALLERGY IN CHILDREN AND THE TARGET ORGAN

1. Gut

2. Skin

3. Lungs

4. Nose

5. Eyes

Egg White

All from 1, plus

Mites

Mites

Moulds

Milk

Mites

Moulds

Pets

Pets

Soy

Animal skin

Pets

Moulds

Mites

Peanuts

Pollens

Cockroaches

Pollen

Pollen

Wheat

Cockroaches

Pollens

Fish

Fruits

Animal skin

Nuts

Eczema is often the first indicator in patients that there may be a problem with allergy and is frequently of long duration and persistent. It is associated with a reduced quality of life and is associated with asthma. At this time the fundamental genetic cause of allergic eczema remains unknown but the risk factors that accelerate the disease progress are well known and mites are among these risk factors.

I
House dust mites, Latin names are Dermatophagoides pteronyssinus and its close cousin D. farinae.

These common house dust mites are scavenger living in dark, damp, warm nest sites such as beds and bedding, upholstered cloth furniture, carpets and soft toys. They are barely visible to the naked eye and when viewed under a microscope appears to be almost transparent. For a mite life depends upon absorbing moisture from its surrounding environment, without adequate moisture the mite colonies will stop breeding and then eventually die out.

Fast facts about house dust mites
Latin names Dermatophagoides pteronyssinus (European) and Dermatophagoides farinae (American) The common house dust mite lives in dark, damp, warn nest sites such as mattresses. It has no eyes, never drinks, yet is 75% water. Its life depends upon absorbing moisture from its surrounding environment. The mites does not breath, but gets oxygen through its outer shell like covering. It eats organic matter including discarded mouldy skin scales found in places like mattresses and pillows. The house dust mite is able to eat and find nourishment from its own droppings. An adult can produce up to 20 droppings a day. The enzymes packaged in the droppings, are the major cause of mite allergic diseases. The enzymes eat away the ‘glue’ that binds delicate lung cells together. Allergic disease from mites are: Asthma, rhinitis, eczema, and conjunctivitis. 80% of asthmatic children in the UK are allergic to the house dust mite

One is seven UK children have asthma

References

The UCB institute of allergy. European Allergy White Paper; Allergic disease as a public health problem.Braine-l’ Alleud: UCB Pharmaceutical Sector, 1997.


‘Dust Mite Allergies and Asthma - A worldwide Problem', Platts Mills TAE, de Weck A, UCB Institute of Allergy, Bad Kreuznach September 1987. Reported in The Journal of Allergy and Clinical Immunology, 1989: 83:416-427


‘The Biology of Allergenic Domestic Mites, An Update’, Barbara J. Hart, 1995 Humana Press Inc, Clinical Reviews in Allergy and Immunology 13:115-133.


‘House Dust Mite Der p 1 Downgrades Defenses of the Lung by Inactivating Elastase Inhibitors’, Brown A, et al, Am.J.Respir.Cell Mol. Biol. 2003 vol 29;381-389