What is Pet Allergy?
[In the United States, about 62% of households have pets] (https://www.aaaai.org/conditions-and-treatments/allergies/pet-allergy). At the same time, millions of Americans are allergic to pets.
The most common pet allergen is dander, the dead skin shed by pets. Other allergens include proteins found in the pet’s urine and saliva. The overreaction of the immune system results in an allergic reaction. The immune system recognizes the protein in the animal’s skin, saliva, or urine as foreign and produces histamine and other chemicals that lead to the symptoms of an allergy.
The pet allergens can even be found in homes that don’t have pets, as you can carry them on your clothing. The allergens can be found on furniture and walls. They spread through the air whenever the animal is petted or groomed, and can stay airborne for a long time.
Signs and symptoms are usually very mild and can be easily managed. The allergy can be life-threatening in rare cases where there is a severe allergic reaction like anaphylaxis. This impairs breathing and can send the body into shock if immediate action is not taken. Anaphylaxis can also lead to cardiac arrest.
Cats and dogs are the leading cause of pet allergies. Other animals like rodents and rabbits can also cause allergies. Animals without fur, rarely cause allergies.
Symptoms of Pet Allergy
The symptoms vary from person to person and can usually occur immediately after consumption or after a few hours. The symptoms are common to those seen in other allergic reactions.
- Runny or stuffy nose
- Nasal congestion causing pain
- Coughing
- Wheezing
- Hives
- Watery, red, or itchy eyes
- Anaphylaxis in severe cases
- Difficulty breathing
- Eczema
- Itchy skin
The Genetics Behind Pet Allergy
Variations in certain genes have been observed in people with pet allergies. Studying these variations can help predict if a person has a higher risk of getting the allergy compared to other people.
HLA-DQB1 Gene
The HLA-DQB1 gene is part of the family of genes that form the human leukocyte antigen (HLA) complex. The proteins produced by these genes play an important role in the immune system of the body. They help in distinguishing between self and foreign proteins and trigger the necessary immune response.
Variations in this gene are found to be associated with asthma and allergic rhinitis.
rs7775228
rs7775228 is an SNP found in the HLA-DBQ1 gene. People with the minor allele, the C allele, are found to have an increased risk of asthma, and [allergic rhinitis] (https://pubmed.ncbi.nlm.nih.gov/22036096/).
The C allele has also been associated with increased sensitivity to dog allergens.
LRRC32 Gene
The LRRC32 gene encodes for a membrane protein that contains 20 leucine-rich repeats. It regulates a key regulator of a growth factor called TGF-B, which is involved in several functions of the immune system.
rs2155219
rs2155219 is an SNP found in the LRRC32 gene. People with the minor allele, G allele are found to have a 1.18X increased risk of allergic sensitization. The TT genotype is found to be associated with allergic rhinitis.
If one or both the parents have any allergies or asthma, the child is more likely to develop a pet allergy.
Identifying Pet Allergy
Skin-prick test: A small amount of purified allergen extract is pricked into the skin on the forearm or back. After 15-20 minutes, if signs of allergy like redness or itching are observed, you’re found to be allergic to that specific allergen.
Blood test: Blood samples are tested for the presence of allergic antibodies against proteins found in pet dander, urine, or saliva. This can indicate how sensitive you are to an allergen.
How to manage pet allergy?
The best way to manage any allergy is to avoid the allergen causing it. This can prevent severe allergic reactions.
Lifestyle:
If you decide to give away your pet, you still need to thoroughly clean your house to get rid of all the allergens. Replace carpets, bedding, upholstered furniture, and vacuum your entire house with HEPA filters.
If you still want to keep your pet, there are certain measures you can take to avoid an allergic reaction.
1. Ask someone else you live with who does not have allergies to give frequent baths to your pet, at least once a week.
2. Make your bedroom a pet-free zone as you would spend most of your time there. This prevents allergens from settling on things in the room.
3. Use air purifiers with HEPA filters to remove allergens in the air. Vacuum your house frequently with machines containing HEPA filters.
4. Remove any furniture, upholstery, and curtains that can collect dander easily. Try to avoid carpets also.
5. Wear a dust mask if you cannot find anyone to help with cleaning your pet.
6. Clean the pet’s kennel, litter box frequently. It would be better if someone without allergies can help with this.
Studies show that being exposed to pets early in life can help avoid allergies.
Medications:
You may need to take allergy medications in addition to taking measures to avoid the allergen. Your doctor may prescribe any of the following medications based on your case:
- Antihistamines
- Decongestants
- Corticosteroids
- Leukotriene modifiers
Treatments:
1. Immunotherapy: This is done through a series of allergy shots. Small doses of allergen are given as weekly shots, and the dosage is gradually increased to get your immune system used to the allergen.
2. Nasal irrigation: A specially designed squeeze bottle or a neti pot can be used to flush the allergen and thickened mucus out of your sinuses. A prepared saline solution is used.
Summary
- Some people are allergic to pet dander, proteins present in the pet’s saliva or urine. This leads to symptoms of allergies. The immune system considers these proteins as foreign and mounts an immune response.
- The symptoms of pet allergy include wheezing, nasal congestion, watery, red, itchy eyes, difficulty breathing, to name a few.
- The C allele of rs7775228, an SNP found in the HLA-DBQ1 gene is associated with an increased risk of asthma and allergic rhinitis. The G allele of SNP rs2155219 found in the LRRC32 gene increases the risk of allergic sensitization. The T allele of the same SNP is associated with allergic rhinitis.
- If asthma or allergies run in your family, you are more likely to get pet allergies.
- A skin-prick test or blood test can be used to diagnose what you’re allergic to.
- Certain lifestyle changes, medications, and treatments can help avoid or manage symptoms of pet allergy.
References
https://www.niehs.nih.gov/health/topics/agents/allergens/pets/index.cfm
https://www.aafa.org/pet-dog-cat-allergies/
https://acaai.org/allergies/types/pet-allergy
https://www.mayoclinic.org/diseases-conditions/pet-allergy/symptoms-causes/syc-20352192
https://www.ncbi.nlm.nih.gov/pubmed/23817569
https://www.snpedia.com/index.php/Rs7775228
https://www.snpedia.com/index.php/Rs2155219
