Allergens in the indoor environment


The mites are microscopic and they are part of the class of arthropods. They prefer warm and humid environments. They are present, sometimes in millions, in the indoor environment and they represent the main allergen found in the dust. They are found in large quantities where the occupants spend most of their time. They are found on mattresses, carpets, stuffed animals ... Mites feed themselves with dead skin particles that fall into the environment. Their faeces contain allergenic proteins produced by two types of mites: Dermatophagoides pteronissinus (Der p) and Dermatophagoides farinae (Der f). For most people, these proteins are not a problem. On other hand, people with allergies, allergic reactions can become very disturbing. Mites can cause allergic rhinitis, asthma, allergic conjunctivitis and chronic sinusitis if they do not bite or cause a skin reaction. The symptoms can be present all year long or more particularly in autumn and during the winter. It is noted that 44% of allergies are caused by mites, so they are the second cause of allergies with dust after those with pollens.

The allergenic proteins of dust mites can end up in the air of house when they are lifted. For example, when sweeping or shaking carpets. In contrast, allergens remain temporarily in the air and then redeposit. A home with a relative humidity of 50% or more promotes the proliferation of mites. Female mites can lay between 25 and 50 eggs every 3 weeks. The amount of mites present in the environment will be decisive for allergic individuals. Several actions can be taken to reduce their presence in the house.

  • Regularly ventilate the house and maintain the temperature between 18 and 20 degrees Celsius;
  • Eliminate carpets and regularly clean floors;
  • Purchase protective covers against dust mites. Synthetic duvets are preferable to those made in feathers since they are easy to wash. Be sure to clean the bedding every 2 weeks at 60 degrees Celsius;
  • Choose anti-asthmatic pillows (washable). Wash them every month;
  • For children, limit the number of fluff and wash them regularly at 60 degrees Celsius (if the soft toy cannot be washed, it can be put in the freezer in a plastic bag for a few hours);
  • Avoid fabric curtains;
  • Avoid fabric curtains;

The pets

All warm-blooded animals (including birds) may have potential to cause allergic reactions in some individuals. Allergenic proteins are found on their skin, hair, urine and saliva. Depending on the individual, a few minutes after animal contact, may appear nasal discharge, redness in the eyes, cough or cutaneous signs (eczema, urticaria). In some people, allergic reactions can be more severe (asthma attack).

The best way to avoid allergic reactions to having allergic problems is to have no pets at home. After the removal of the animal in question, it takes an average of five (5) to six (6) months before seeing all traces of allergens in the home. When it is impossible to remove the animal from the environment, it is possible to take preventive measures. On the other hand, people exposed may increased risk of being asthmatic in the long term.

  • Install an air purifier with HEPA filter;
  • Do not give access to the animal to the room;
  • Do not admit animals on the couches;
  • Wash hands after contact with the animal;
  • Wash cats once a week;
  • Wash dogs twice a week.

Anyone with a weakened immune system should not, as a precaution, be exposed to the presence of domestic animals, which have allergenic and/or irritating potential (hair and feathers). In addition, the faeces and urine of animals have a great potential for bacterial production. This applies to felines, canines, rodents and birds.

Cockroaches (cockroaches)

Cockroaches are insects that love darkness, heat and humidity. They are often found in kitchens and bathrooms. They are also responsible for an increase of respiratory allergies. People who are allergic, allergic reactions can manifest as rhinitis and asthma attacks. It is important to have the house remediated by specialists when cockroaches are found inside. To prevent the occurrence of cockroaches in the indoor environment, prevention measures can be applied.

  • Keep the environment clean and healthy;
  • Disinfect floors and cupboards regularly;
  • Use closed garbage with plastic bags;
  • Keep foods in airtight containers;
  • Avoid leaving leftover food on kitchen counters or on the dining table;

Laboratory analyzes can detect the presence of Bla g1 protein produced by Blatella germanica. These allergenic particles are present in excrement, saliva, body and exuviates of cockroaches. These allergens can be found in the air of a home when there is a chronic or even occasional infestation.