One look at a cockroach walking on your kitchen floor or slab, and you rush to get it right out of your home! Cockroaches are icky pests that are known to spread germs and cause diseases. But, did you know, just like other animals, birds, and pollen, people can be allergic to cockroaches too?
You will be shocked to know that around 78%-98% of homes in urban areas contain cockroaches, and about 60% of the people with asthma who live in cities are allergic to cockroaches. A protein found in cockroaches triggers an allergic reaction in some people.
Like any allergy, cockroach allergy gets triggered by an allergen, often an enzyme (a type of protein) released from the body of roaches. This allergen is found in the cockroach’s saliva, waste, and body parts and spreads everywhere the cockroach goes. Coming in contact with these cockroach proteins can trigger an allergic reaction.
Symptoms of Cockroach Allergy
In people who are allergic to cockroaches, common symptoms include:
- Uncontrolled sneezing
- Runny or stuffy nose
- Itchy, red, and watery eyes
- Itchiness in throat, mouth, and nose
- Cough
- Skin itch and skin rash
In asthmatics, symptoms of cockroach allergy include:
- Wheezing
- Chest tightness
- Breathing trouble
- Whistling sound while breathing out
Cockroach Allergy and Asthma
Cockroach allergy has been reported as an important cause of asthma for over 50 years. Many studies that have been conducted so far establish a positive correlation between cockroach allergy and the development of asthma. The main reason for this is environmental exposure and sensitization to the various species of cockroaches that exist in the world today. In fact, this sensitization to cockroach allergens is the biggest risk factor for the development of asthma in low-income populations in urban setups.
How Does Genetics Contribute To Cockroach Allergy?
There are many genes and polymorphisms that have strong associations with this condition, particularly the genetic variants in TSLP, MBL2, CD14, and IL-12A genes.
IL-12A Gene
One particular gene, the IL-12A or Interleukin 12, and its variants influence cockroach allergy in children with asthma. IL-12A is involved in immune responses, especially the one involving T cells. IL-12A also has a role to play in the pathogenesis of asthma. The gene is located on the p-arm of chromosome 3.
Variations in The IL-12A Gene
Two SNPs, rs2243123 and rs2243151, associated with the IL-12A gene, have shown a risk of increased allergic susceptibility to different species of cockroaches
The presence of the T allele in SNP rs2243123 is associated with an increased risk of cockroach allergy with respect to the two common cockroach species P. Americana and B. germanica.
The presence of the A allele in SNP rs2243151 is associated with an increased risk of cockroach allergy.
Non-Genetic Influences on Cockroach Allergy
From the many studies performed on cockroach allergy and its association with asthma, non-genetic risk factors that increase one’s risk of developing the cockroach allergy include:
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Low socio-economic status: People from low socio-economic segments living in urban cities are at an increased risk of developing cockroach allergy as they are exposed to cockroaches more often and get sensitized to them.
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Race: African-Americans are at an increased risk of developing the condition.
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Pre-existing asthma: People who have atopic or other types of asthma are at an increased risk of developing cockroach allergy. In fact, cockroach allergy is the most common indoor allergy that asthmatics suffer from.
Recommendations for Managing Cockroach Allergy
Lifestyle modifications:
Individuals who are allergic to cockroaches need to make a few lifestyle modifications to avoid cockroaches as much as they can. Here’s what you can do:
- Always cover all your trash/garbage bins.
- Keep food, both cooked and uncooked, in airtight containers with proper lids.
- Clean up any food spills, crumbs, oil, etc., from the stovetop, counters, tables, and floor as these can attract cockroaches.
- Cockroaches like damp places. So, look out for any leaking pipes in your home and seal any cracks in the floor or walls from where cockroaches can enter the house.
- Use anti-cockroach sprays, gels, and traps to drive out or kill existing cockroaches from your house.
Cockroaches are common members in most homes, and an allergy to them is a very common occurrence too. If you suspect you have a cockroach allergy, or your symptoms seem to be getting worse, visit your doctor immediately to help bring it under control. A simple blood test or skin test can help diagnose if you or your loved one is allergic to cockroaches.
Summary
- Cockroaches are common members in most homes, so are cockroach allergies. It is rather surprising to know that a pest that is found in homes all over the world can trigger an allergy.
- The condition shows common allergic symptoms, and has a strong genetic component, and affects some races more than others.
- Variations in the IL-12 gene, associated with immune system responses, have been associated with an increased risk for cockroach allergies.
- A few lifestyle modifications, maintaining cleanliness and hygiene around the house can help prevent an allergic reaction. If you suspect you have a cockroach allergy, or your symptoms seem to be getting worse, visit your doctor immediately to help bring them under control. A simple blood test or skin test can help diagnose if you or your loved one is allergic to cockroaches.
References
https://www.aafa.org/cockroach-allergy/https://acaai.org/allergies/types/cockroach-allergy
https://pubmed.ncbi.nlm.nih.gov/8648037/
https://www.jacionline.org/article/S0091-6749(96)70209-9/fulltext
https://www.healthline.com/health/cockroach-allergy#bottom-line
https://www.webmd.com/allergies/nasal-allergy-trigger-cockroaches
https://www.nationaljewish.org/conditions/allergy/overview/allergens/cockroach
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2525650/
