Introduction
Cat allergies refer to allergic reactions triggered by exposure to proteins found in cat dander, saliva, or urine. When people with cat allergies come into contact with these allergens, their immune system mistakenly identifies the proteins as harmful and releases histamine to defend against them. This causes allergy symptoms like sneezing, coughing, and itchy eyes. Cat allergies are estimated to affect 10-20% of the population and can range from mild to severe.
Prevalence
It is estimated that globally around 10-20% of human adults are allergic to cats, a figure that has been increasing over time. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8721548/ Allergies to cats affect 10 to 20% of the world’s population. https://aafa.org/allergies/types-of-allergies/pet-dog-cat-allergies/ About 10 percent of people are allergic to household pets like cats. https://www.litter-robot.com/blog/cat-allergies-why-are-so-many-people-allergic/
Symptoms
The most common symptoms of cat allergies include:
- Sneezing and runny nose (https://acaai.org/allergies/allergic-conditions/pet-allergies/)
- Itchy, red, watery eyes (https://www.mayoclinic.org/diseases-conditions/pet-allergy/symptoms-causes/syc-20352192)
- Nasal congestion
- Itchy nose, roof of mouth, or throat
- Coughing
- Wheezing and chest tightness
- Facial pain and pressure
People allergic to cats may experience symptoms shortly after exposure to cat dander or saliva. Symptoms can range from mild to quite severe.
Causes
Cat allergies are caused by an overreaction of the immune system to proteins found in cat dander, saliva, or urine. These proteins are known as allergens. When people with cat allergies are exposed to these allergens, their immune system mistakenly identifies them as harmful invaders and releases IgE antibodies to attack them. This triggers the release of chemicals like histamine which lead to allergy symptoms.
The most significant cat allergen is a protein called Fel d 1, which is found primarily in cat skin flakes or dander. Cats produce Fel d 1 in their sebaceous glands and the protein gets distributed throughout their fur as they groom themselves. All cats produce Fel d 1, though levels vary between breeds. Exposure to Fel d 1 is the primary cause of cat allergies in people. Other proteins found in cats like Fel d 2 (present in saliva) and Fel d 4 (found in urine) can also trigger allergic reactions.
In essence, when someone with a cat allergy comes into contact with these allergens through activities like petting or playing with a cat, the protein triggers an IgE mediated immune response that leads to the bothersome symptoms of cat allergies. The immune system of people with cat allergies overreacts to harmless proteins from cats.
Risk Factors
Several factors have been shown to increase the risk of developing cat allergies. According to research published in the journal Clinical & Experimental Allergy, the strongest risk factor is having a family history of other allergies, especially respiratory allergies like hay fever [1]. People with asthma are also at higher risk of developing cat allergies [2]. Additional risk factors include:
- Having elevated total IgE antibody levels
- Sensitization to other allergens like dust mites or pollen
- Presence of other allergic conditions like eczema
- Exposure to cats at a young age
Understanding these risk factors can help identify individuals more prone to developing cat allergies later in life.
Diagnosis
Cat allergies are diagnosed through a combination of medical history, physical examination, and allergy testing. According to the Mayo Clinic (https://www.mayoclinic.org/diseases-conditions/pet-allergy/diagnosis-treatment/drc-20352198), a doctor will ask about symptoms and when they occur to help determine if an allergy is likely. They may also examine the nose for signs of inflammation. Allergy testing can confirm a cat allergy and identify the specific allergen.
Common allergy tests include skin prick testing, where allergens are pricked into the skin to look for a reaction, and blood tests that measure levels of IgE antibodies to different allergens. High levels of antibodies indicate an allergy. Patch testing may also be done by placing cat allergens on the skin for 2 days to check for a reaction. Allergy testing can identify the specific cat proteins that trigger an allergic response in an individual.
In some cases, an allergist may recommend an oral food challenge where cat dander is ingested in a medical setting to definitively confirm or rule out a cat allergy. This is considered the gold standard for diagnosis but carries a small risk of triggering an allergic reaction.
Treatments
There are several treatment options available for people with cat allergies. The main treatments include medications, immunotherapy, and allergen avoidance.
Medications
Antihistamines like cetirizine (Zyrtec), loratadine (Claritin), and fexofenadine (Allegra) can help relieve allergy symptoms (Mayo Clinic). These medications block the effects of histamine, which the body releases when having an allergic reaction. Nasal corticosteroid sprays like fluticasone propionate (Flonase Allergy Relief) and triamcinolone (Nasacort Allergy 24HR) can also reduce inflammation in the nasal passages.
Immunotherapy
Allergy shots or sublingual (under the tongue) allergy tablets containing small amounts of cat allergens can help desensitize the immune system over time. These allergen-specific immunotherapies work by gradually exposing the body to cat allergens to increase tolerance.
Allergen Avoidance
The most effective way to manage cat allergies is to avoid exposure to cat allergens. Keeping cats out of the bedroom and restricting them to certain areas can help reduce allergen levels in the home. Using high-efficiency HEPA air purifiers and vacuums with HEPA filters can also help remove allergens from the air and surfaces.
Managing Allergies
If you want to live with a cat despite your allergies, there are ways to manage the symptoms. According to the OSU Veterinary Medical Center, the most effective approach is to reduce exposure to allergens as much as possible [1]. Here are some tips for minimizing allergen exposure:
- Keep cats out of your bedroom and restrict them to certain areas of the home.
- Bathe your cat weekly to reduce levels of Fel d 1 allergen in dander. Use a cat-safe shampoo and brush thoroughly while bathing.
- Consider wiping your cat down daily with damp cloths to pick up surface allergens.
- Groom your cat frequently to reduce loose fur and dander.
- Use HEPA air filters in rooms where your cat spends time.
- Vacuum carpets and furniture regularly using a HEPA filter vacuum.
- Wash bedding weekly in hot water to destroy allergens.
- Consider getting covers for mattresses, box springs, pillows and upholstered furniture.
In addition to environmental controls, medications can help relieve allergy symptoms. Antihistamines, decongestants, nasal sprays and allergy shots are options that may provide symptom relief. Talk to an allergist to determine the best medical treatments for your cat allergy.
Hypoallergenic Cats
Some cat breeds are less likely to cause allergic reactions in people sensitive to cats. This is because they produce lower levels of Fel d 1, the allergen found in cat saliva, urine, and dander.[1] While no cat is completely non-allergenic, the following breeds may be better tolerated:
Siberian – Siberians have a thick double coat, but produce lower levels of allergens. Their dander contains less of the Fel d 1 protein.[2]
Russian Blue – Their short, dense coat produces less dander and may contain lower Fel d 1 levels.
Balinese – Closely related to Siamese cats, Balinese have less undercoat so they shed less dander and fur.
Oriental Shorthair – Produces less dander due to its fine, short coat.
Devon Rex – Sheds little fur due to its curly, short coat.
Cornish Rex – Very little fur or dander due to its thin, wavy coat.
While considered hypoallergenic, reactions can still occur. Meeting the cat breed, spending time in the home environment, and gradually exposing oneself to the cat can help determine if you will have an allergic reaction.
Outlook
The prognosis for people with cat allergies is generally good. While there is no cure for cat allergies, symptoms can be managed through medications, allergy shots, and avoiding exposure to cats. With proper treatment, most people with cat allergies can control their symptoms and live normal lives.
Allergy medications like antihistamines and nasal steroids can provide significant symptom relief for many people. Allergy shots, also known as immunotherapy, can gradually desensitize the immune system to cat allergens over time. Though the shots take commitment, they can potentially lead to long-term reduction in symptoms.
Lifestyle changes like keeping cats out of the bedroom, using high-efficiency air filters, washing hands after contact, and vacuuming frequently can also help reduce exposure to allergens. While complete avoidance of cats may be necessary for some, many people find they can successfully manage living with a cat through medications and environmental controls.
Though cat allergies have no cure, the many effective treatment options allow most people to control their symptoms. By working closely with an allergist to find the right approach, people with cat allergies can often achieve an excellent prognosis and quality of life.
