Managing Cat Allergies: What Causes Them and What Actually Helps

Jul 3, 2025

Written by: Pacagen Team
Reviewed by: David Zhang, PhD
David is an immunologist, bioengineer, and a scientific advisor at Pacagen.

If cuddling your cat leaves you sneezing, congested, or with itchy eyes, you’re not alone. Cat allergies are incredibly common, affecting millions of people in the U.S. alone. But what actually triggers these reactions, and what can you realistically do about it? Let’s break it down.

What really causes cat allergies?

Contrary to popular belief, it’s not cat fur itself that’s to blame. According to veterinarian Dr. Andrew Findlaytor, DVM,

“Cat allergies are primarily caused by an allergen called Fel d 1. Fel d 1 is typically found in cats’ saliva, skin and urine.”

Here’s how it works:
When cats groom themselves, Fel d 1 sticks to their fur. As they shed, the allergen becomes airborne and ends up on surfaces, in the air, and unfortunately—for allergy sufferers—in your lungs, nose, and eyes.

Dr. Findlaytor further explains that three key factors determine how allergenic a cat might be:

Fur Length: Longer hair means more surface area for allergens to hitch a ride.
Grooming and Shedding Frequency: Cats who groom and shed more spread more Fel d 1.
Fel d 1 Production Levels: Some cat breeds naturally produce more Fel d 1 than others.

To make matters worse, Fel d 1 is extremely persistent. According to the American College of Allergy, Asthma & Immunology, it can linger on surfaces for 20–30 weeks, even in places where no cats currently live.

Cat Allergies

Why managing cat allergens is so tough

Cat allergens are lightweight and easily airborne—unlike dust mite allergens, which mostly stay on surfaces unless disturbed. Studies have shown that in a home with a cat, the amount of airborne Fel d 1 you breathe in daily can be comparable to the yearly exposure you’d get from pollen or dust mites.

“If there is a cat present at home, the amount of cat allergens you breathe in a single day (up to 0.3 µg/day of Fel d 1) is comparable to the amount of pollen or dust mites you would inhale in an entire year (~0.5 µg/year),”
- N. J. Custis, 2003.

Even rehoming a cat isn’t an instant fix. Because of Fel d 1’s long half-life and sticky properties, symptoms can persist for months afterward.

How cat allergies actually work in your body

So why does your body react so strongly to something as tiny as Fel d 1?

Harvard immunologist Dr. David Zhang, PhD, breaks it down:

“At a high level, allergic responses are driven by about half a dozen key contributors in your immune system, which work together in complex, but very cool ways to give rise to a vast range of symptoms.”

Here’s how that works:

When you first get exposed to cat allergens, your body creates IgE antibodies that attach to immune cells like mast cells and basophils.
Next time you encounter the allergen, those cells release histamines and other chemicals.
The result? Sneezing, congestion, itchy skin, watery eyes, and more.

Dr. Evan Zhao, PhD, further explains:

“Upon subsequent exposure to the specific allergen—whether through inhalation, ingestion, or contact with the skin or eyes—a chain reaction is triggered... these cells release different mediators, including histamines, to ‘fight’ the intruding allergens, even though there is nothing harmful to fight.”

What actually helps: real-world solutions

Managing cat allergies takes a multi-step approach. Here’s what experts recommend:

1. Modify Your Environment

Vacuum with HEPA filters
Use allergen-proof bedding
Dust and mop regularly
Use materials like leather, wood, plastic and limit fabric surfaces where allergens can settle (like rugs)
Replace carpets with hard flooring and avoid wall to wall rugs

2. Adjust Your Habits

Wash your cat’s bedding weekly in hot water that is at least 130°F
Groom your cat regularly—but ideally, do it outside
Keep your bedroom a pet-free zone.
Dr. Findlaytor recommends: “Having a safe spot to rest is extremely important for your immune system to recharge, especially if you are having a bad allergy day.”

3. Medical Treatments

Options include:

Antihistamines: Good for fast relief but can cause drowsiness*
Nasal corticosteroids: Reduce inflammation but may cause nasal irritation*
Allergy immunotherapy: Long-term solution, but takes months to years and doesn’t work for everyone

*First-generation antihistamines like diphenhydramine (Benadryl)

4. Biotech-Based Solutions

Recent scientific advancements are offering new hope. Pacagen researchers, including Dr. Evan Zhao, PhD, and Dr. Siyang Han, PhD, have bioengineered proteins called WhiskerBlock Alpha, designed to neutralize Fel d 1 at the source—before it even triggers symptoms.

For example:

A cat spray for neutralizing Fel d 1 in the air and on surfaces
A cat food topper that helps reduce allergens directly in your cat’s saliva

As Dr. Zhao explains:

“The allergen neutralizing formula harnesses the power of naturally engineered proteins to precisely target and neutralize specific allergens, including cat, dog, and dust mite allergens, making them effective compared to other medical treatments and harmless to the surrounding environment.”

Final thoughts

There’s no single “magic cure” for cat allergies—but with the right mix of environmental controls, habit changes, medical support, and science-backed innovations, you can absolutely make life with a cat more manageable.

If you’re struggling, talk to your doctor about your symptoms and explore all your options—from tried-and-true antihistamines to next-gen allergen neutralizers.

After all, life with your cat should be filled with purrs and not sneezes.