Introduction
Cat allergies are caused by an overreaction of the immune system to proteins found in cat dander, saliva or urine [1]. When exposed to these allergens, the body releases histamine and other chemicals that cause allergy symptoms. Cat allergies are one of the most common allergies, affecting 10-20% of the global adult population [2].
Symptoms
Some of the most common symptoms of cat allergies include sneezing, runny nose, itchy eyes, coughing, and skin rashes (Source 1). Sneezing and nasal symptoms tend to occur rapidly after exposure to cats due to an allergic reaction. Sneezing fits and a runny nose are frequently experienced by those allergic to cats (Source 2). Itchy, red, and watery eyes are also very common. Allergens from cats can irritate the eyes and cause itching, swelling, and discharge. Coughing may also occur from irritation to the throat and airways. Some individuals may develop hives or eczema flares after contact with cats. Skin reactions are caused by an immune response that releases histamine, leading to itching, redness, and swelling.
Causes
Cat allergies are caused by an overreaction of the immune system to allergens found in cat dander, saliva, and urine (https://www.webmd.com/allergies/cat-allergies). The primary allergen is a protein called Fel d 1, which is present in cat skin flakes known as dander (https://vet.osu.edu/sites/vet.osu.edu/files/legacy/documents/pdf/education/mph-vph/allergic%20to%20your%20cat.pdf). When inhaled by a person sensitive to it, Fel d 1 triggers an allergic reaction. Cat saliva and urine also contain allergens that can cause symptoms when they land on the skin or are transferred to the eyes. For people with cat allergies, contact with these allergens leads to an overproduction of antibodies called immunoglobulin E (IgE). The interaction between IgE antibodies and cat allergens releases histamine and other chemicals that cause the symptoms of an allergic reaction.
Risk Factors
Certain factors can increase your risk of developing cat allergies:
Family history: Having a parent or sibling with cat allergies puts you at higher risk. Allergies often run in families. According to one study, having one allergic parent tripled the risk of developing a cat allergy [1].
Other allergies: People with allergies to other substances like dust mites, mold, pollen, or livestock are more likely to develop cat allergies as well. Having multiple allergies indicates a sensitive immune system that is prone to overreacting [1].
Asthma: Those with asthma have inflamed airways, which makes them more vulnerable to cat allergens. Asthma patients are 3-4 times more likely to have cat allergies compared to the general population [2].
Complications
If cat allergies are left untreated, they can lead to complications like worsening asthma and respiratory infections. According to Healthline, ongoing exposure to cat allergens can worsen asthma symptoms in people who already have asthma. Asthma complications from untreated cat allergies include more frequent asthma attacks, decreased lung function over time, and increased need for asthma medications.
Sinus and ear infections are also potential complications of untreated cat allergies. The postnasal drip caused by cat allergies can lead to sinus infections, also called sinusitis. Repeated sinus infections, in turn, can cause ear infections like otitis media as drainage flows down the back of the throat into the ears. According to Vet Derm Clinic, chronic nasal inflammation from allergies increases susceptibility to secondary bacterial and yeast infections in pets. This likely holds true for human infections as well.
Overall, leaving cat allergies undiagnosed and untreated can result in problematic respiratory complications. It’s important to see an allergist and follow treatment recommendations in order to prevent complications and maintain health.
Testing
There are two main ways to test for cat allergies:
Skin Prick Test
A skin prick test can help confirm a cat allergy. During this test, a doctor or nurse will prick the skin on the arm or back with a solution containing cat allergen extracts. If a raised bump (hive) develops within 15 minutes, it indicates an allergy to cats [1].
Blood Test
A blood test looks for antibodies called immunoglobulin E (IgE). A high level of IgE antibodies specific to cat dander indicates an allergy to cats [2]. This test is less sensitive than a skin prick test.
Treatment
The most effective treatment for cat allergies is avoidance and minimizing exposure to allergens. This involves keeping cats out of bedrooms and restricting them to non-carpeted areas, grooming the cat frequently, and vacuuming, changing filters, and dusting regularly. Medications can help manage symptoms. Antihistamines like cetirizine (Zyrtec) or fexofenadine (Allegra) can reduce sneezing, runny nose, and itchy eyes. Intranasal corticosteroids like fluticasone (Flonase) can relieve congestion and nasal itchiness. Immunotherapy or allergy shots can decrease sensitivity over time by exposing someone to small amounts of cat allergen.
Some key treatments include:
- Avoidance of cats or minimizing exposure to cat allergens through keeping cats out of bedrooms, restricting access, and cleaning regularly [1]
- Antihistamines like cetirizine or fexofenadine to reduce allergy symptoms [2]
- Nasal corticosteroids like fluticasone to relieve nasal congestion and itchiness [2]
- Allergen immunotherapy or allergy shots to gradually decrease sensitivity over time [2]
Managing an Allergic Reaction
If you have an allergic reaction to cats, there are several medications that can help provide relief from symptoms:
Antihistamines like diphenhydramine (Benadryl), loratadine (Claritin), or cetirizine (Zyrtec) can help relieve sneezing, runny nose, watery eyes, and itching. They work by blocking the effects of histamine, the chemical released by the immune system during an allergic reaction. Antihistamines come in pill, liquid, and nasal spray forms.
Decongestants such as pseudoephedrine or phenylephrine constrict blood vessels in the nasal passages, reducing swelling and congestion. They are available as oral medications or nasal sprays.
Corticosteroids like fluticasone propionate (Flonase) help reduce inflammation. They are administered as a nasal spray and work best when used proactively before allergy symptoms start. Oral corticosteroids like prednisone may be prescribed for short-term use in severe cat allergy cases.[1]
Combining an antihistamine with a decongestant or nasal steroid spray may provide greater symptom relief than taking one medication alone. It’s important to carefully follow dosage instructions.
Prevention
The most effective way to prevent cat allergy symptoms is to keep cats out of bedrooms and limit exposure. According to this source, keeping the cat out of the bedroom can significantly reduce cat allergens. Using HEPA filters in the bedroom can also help filter out allergens. Frequent cleaning and vacuuming with a HEPA filter vacuum can reduce levels of cat dander in the home.
Washing cats weekly can reduce airborne allergens. It’s also helpful to groom cats frequently to remove loose hair and bathe them at least once a week. Wiping cats down with a damp cloth can also reduce dander between full baths. Creating an allergen-free zone and keeping cats in certain rooms can limit exposure in the rest of the home.
When to See a Doctor
You should see a doctor if you experience symptoms of a severe allergic reaction to cats. Signs that warrant immediate medical care include:
- Difficulty breathing – Shortness of breath, wheezing, tightness in the chest, coughing, or choking can signal anaphylaxis, a life-threatening reaction that requires epinephrine.
- Recurrent infections – Allergies can make you prone to sinus infections, ear infections, pneumonia, and other illnesses. Seek help if you get frequent respiratory infections.
- Poor quality of life – If allergy symptoms like congestion, rash, or asthma cause persistent discomfort and severely impact your daily activities, see an allergist.
In addition to acute symptoms, it’s important to have chronic cat allergies evaluated. Left untreated, allergies can worsen over time. An allergist can test for specific allergies and prescribe medications or immunotherapy to help prevent symptoms.
