House Dust Mites or dust mites belong to the spider family and are small and microscopic beings present everywhere. They are 1/3rd of a millimeter in size and look like a small white bug.
Did you know that dust mites are present all over the world except in Antarctica? If you seem to have allergic reactions all through the year, then it could mean that you are allergic to dust mites.
Dust mites love humid and slightly warm temperatures and have strong survival skills. While there are up to 13 types of dust mites present, the three common types that could be present in your house are:
1. American house dust mites
2. European house dust mites
3. Mayne’s house dust mites
House mites feed on the dead skin flakes of humans and other animals. Since human beings shed 30,000-40,000 dead skin cells every minute, there is always so much food for dust mites to eat, flourish, and reproduce.
About 100,000 dust mites live in each square yard of your home carpet. The mattresses you sleep in have hundreds of thousands of dust mites happily living and reproducing.
If your pillow is 2+ years old, up to 10% of the weight of your pillow could be from dust mites and their droppings!
What is a Dust Mite Allergy?
People are usually not allergic to live dust mites. However, they react negatively to the droppings of these mites and the dead bodies of these mites. Every dust mite leaves behind at least 20 droppings a day. Imagine your mattress having 500,000 dust mites. That means every day, your mattress is filled with 10,000,000 new mite droppings!
Each dust mite can live for about 2-3 months. Female dust mites lay 60-100 eggs during their lifespan. As a result, the number of dust mites in your house multiplies every day.
This is the reason people’s allergic reactions to dust mites increase with time.
Symptoms of Dust Mite Allergy
If you are allergic to the dead mites and droppings of dust mites, then you can have the below allergic reactions.
- Sneezing
- Watery eyes
- Red and itchy eyes and nose
- Postnasal drip (dripping flow of mucus from the nose to your throat)
- Itchy and red skin
- Coughing and wheezing
- Shortness of breath
How Does Genetics Contribute To Dust Mite Allergy?
IL10 Gene
The IL10 gene produces the interleukin 10 protein. This protein plays a role in bringing down inflammation in the body. This is considered a good gene and brings down the unwanted effects of immune responses.
[The GG genotype of the rs3024496 SNP of this gene brings down the activity of the interleukin 10 protein and hence increases the risk of asthma when exposed to dust mites] (https://www.jacionline.org/article/S0091-6749(08)00599-X/fulltext).
rs117902240
The AC genotype of the rs117902240 SNP decreases FEV1 capacity and increases the risk of asthma attacks when exposed to excessive dust mites. FEV1 is a measure of a person’s vital capacity.
rs115997623
The minor T allele of the rs115997623 SNP is considered risky and is associated with reduced FEV1 function and an increased risk for asthma attacks with exposure to dust mites.
Non-genetic Influences On Dust Mite Allergy
Industrial settings: People who live in highly industrialized areas are exposed to more dust pollution and dust mites. These individuals have a higher chance of developing dust mite allergy.
Heredity: Though rare, dust mite allergy can run in the family. If your grandparents or parents have had dust mite allergies, the chances are that you develop it too.
Age: Infants and children are at higher risk for developing dust mite allergies than adults.
Exposure to excessive dust mites early in life: If a person has been exposed to excessive dust mites very early in life, he/she is at more risk for developing a dust mite allergy.
Smoking: Cigarette smoking can damage the airway epithelial cells. The airway epithelium is a column-like structure in the respiratory tract that prevents allergens and external elements from entering the tract. Tobacco smoke kills these cells and makes you vulnerable to dust mites. [Smoking also worsens symptoms of dust mite allergies] (https://pubmed.ncbi.nlm.nih.gov/10340943/).
Asthma and other allergies: 75% of children and 50% of adults with asthma are also diagnosed with other forms of allergies. Up to 85% of people with asthma and other allergies end up being allergic to house mites. This relationship between these different kinds of allergies makes it difficult to treat the underlying condition.
Managing Dust Mite Allergy
Confirm dust mite allergy
There are so many substances that can cause allergies and it is important to understand if you are allergic to dust mites. Here are some tests/diagnostic methods that help with the confirmation:
- IgE blood test - This blood test looks for IgE antibodies in the blood to identify if the person is having an adverse reaction to dust mites.
- Skin prick test - Exposes the skin to a small amount of dust mite allergen and checks the reactions.
- Atopic patch tests - Atopic patch tests make use of delayed reactions and the presence of T cells in the body to diagnose dust mite allergies.
- Basophil activation tests - Basophils are types of White Blood Cells that fight against external allergens. These tests look for basophil activation markers to know if a person is having an allergic reaction to dust mites.
Cover mattresses and pillows with thicker fabrics and plastic sheets
By covering mattresses with plastic sheets in the morning, you can prevent the penetration of dust mites into the mattress surface. Thicker and finely woven fabric covers in the night prevent dust mites from penetrating from the mattress to your body.
Don’t use carpets unless necessary
If not needed, carpets can be removed from floors, as this helps bring down dust mite growth at home.
Wash bedding in hot water
Make sure you wash your bedding at least once a week in hot water to kill dust mites. Drying the bedding in bright sunlight also helps kill existing mites.
Use air filters
Air filters or air purifiers come with HEPA (high-efficiency particulate air) filtration system and can eliminate microscopic dust mites and their particles from the room.
Use dehumidifiers
Dehumidifiers are appliances that help bring down the humidity levels in a room. If you live in a humid area, using these can help bring down the growth of dust mites.
Acaricide cleaners
Acaricides are kinds of pesticides used in killing dust mites and ticks. These are toxic in nature and need to be used with caution. Most people take the help of professional cleaners who use acaricide based products to get rid of mites.
Antihistamine sprays and drugs
Since dust mites cause general allergic reactions in the body, treating the reactions with antihistamine sprays and over the counter drugs help.
House dust mites allergen immunotherapy
This immunotherapy practice is also called desensitization. This involves injecting minute doses of the allergen (dust mites in this case) to the individual over a period of time to decrease sensitivity.
The injections are offered in regular periods for around 24 weeks, and this will be followed by 3-5 years of monthly maintenance schedules. This process gives permanent relief and reduces the flaring up of dust mite allergic symptoms.
Summary
- Dust mites are microscopic bugs that belong to the spider family. Hundreds of thousands of dust mites are present on all surfaces around you.
- Dust mites survive in humid and warm temperatures. The dead bodies and droppings of dust mites cause allergic reactions in human beings.
- The symptoms of dust mite allergy include watery eyes and nose, redness in eyes and nose, sneezing and coughing, and shortness of breath.
- Variations in the IL10 gene increase a person’s risk of developing asthma attacks because of dust mites. Few other SNPs also decrease FEV1 capacity and cause symptoms like shortness of breath and cough when the person is exposed to excessive dust mites.
- People living in industrial settings, habits like smoking, and asthma, and other allergies all result in an increased chance of dust mite allergy flare-ups.
- Washing bedding regularly in hot water, using air filters and dehumidifiers, and cleaning surfaces using acaricide products can all help handle house dust mites.
References
https://www.ncbi.nlm.nih.gov/books/NBK447098/
https://www.mayoclinic.org/diseases-conditions/dust-mites/symptoms-causes/syc-20352173
https://www.healthline.com/health/allergies/dust-mites#treatment
https://www.aafa.org/dust-mite-allergy/
https://acaai.org/allergies/types/dust-allergy
