Name:House dust mites

Scientific name:Dermatophagoides pteronyssinus, Dermatophagoides farinae 

Description:

Mites are distantly related to spiders and have eight legs. Measuring between 0.2 and 0.4 millimeters in length, they are invisible to the naked eye. They only live for about six weeks but, given propitious conditions (relative humidity of between 65 and 80%, and a temperature of between 20 and 30°C), they reproduce at a staggering rate with the females being able to lay an egg as often as every day.
They live on dead human and animal skin, and hair and nail debris.

Where they are found:

In temperate climates, mites proliferate inside houses and they can be found even in the cleanest in bedding, curtains, stuffed toys, sofas, carpets and rugs. One mattress can be home to two million mites, and just one gram of dust can contain as many as 2,000!

Period of exposure:

Year-round

Major allergens:

Der p 1 (25 KDa), Der p 2 (14 KDa), Der p 3 (28-30 KDa).

Allergy:

House dust mites account for 50% of all cases of allergy. It is the dead organisms and their dejecta which induce allergic reactions. When inhaled, the symptoms affect the airways, e.g. rhinitis or asthma, and when these materials come into contact with the skin, they cause atopic dermatitis. The severity of symptoms tends to peak in Autumn and through Winter when interiors are heated most and aired least.
Mites cannot survive at high temperature (60°C) or when the air is very dry. To protect against house dust mites, carpets, wall-coverings, padded sofas and chairs, stuffed toys and curtains should all be avoided; bedding should be washed regularly at a temperature of 60°C and the mattress should be fitted with a medical-grade, anti-house dust mite cover. Rooms should not be heated to more than  18°C, and they should be regularly aired.

Cross-reactions:

Shrimps, cockroaches, snails.

Tyrophagus putrescentiae