Atopic Dermatitis in Cats

Atopy is a common skin condition in cats, but can be difficult to differentiate from other inflammatory processes or allergic reactions. Chronic pruritus (itchy skin) should be assessed by a veterinarian, particularly if accompanied by signs of hair loss or skin injury.

Itchy and/or inflamed skin is not typically an emergency; however, cats with severe allergies that show signs of anaphylaxis (rapid, open-mouthed breathing, pale gums, collapse) require emergency veterinary care.

Atopy is characterized by itching on more than one area of the body. Cats experiencing itchy skin may scratch, rub, chew, lick, and groom themselves excessively.

Symptom severity may vary and may be transient or seasonal.

Severe atopic reactions may result in visible rashes or lesions on the skin. Hair loss and skin damage may result from over-grooming.

Flea allergy, food allergies, mite infestation, fungal infection, and other skin disorders may cause symptoms identical to atopic dermatitis, and must be ruled out.

Atopic dermatitis is caused by an immune hypersensitivity to environmental allergens that leads to inflammation of the skin.

Common allergens include dust, pollen, or mold.

There is no test to directly diagnose atopic dermatitis. Atopic dermatitis is diagnosed by excluding other diagnoses, using tests including:

• Examination for fleas or visible parasites
• Skin scraping and cytology
• Fungal culture
• Allergy tests (intradermal test, blood test)
• Elimination diet
• Medication trial (e.g. antibiotics if infection is suspected)
• Skin biopsy

If atopic dermatitis is suspected, treatment can include medication such as steroids, immune-modulating medication, anti-itch medication, and/or antihistamines. Dietary supplements such as Omega-3 and Omega-6 fatty acids may be recommended.

Treatment for fleas may be required to rule out flea bite allergy.

If secondary infections have developed, antibiotic or antifungal medication may be required.

Hyposensitization, also known as allergen-specific immunotherapy, or allergy shots, may moderate the allergic reaction causing dermatitis and reduce the need for other treatments. This treatment requires long term commitment and supervision by a veterinarian.

Avoidance of allergens may be recommended but identifying specific allergens and eliminating exposure may not be possible.

Atopic dermatitis may develop at any age, but often affects younger cats (< 5 years old). Atopy is associated with a genetic predisposition to allergic hypersensitivity, and the condition is life-long. Cats with atopy can live healthy lives with treatment, but need to be monitored for flare-ups, changes in symptoms, and for secondary infections.

Atopic dermatitis occurs in cats that are genetically predisposed to environmental allergies. Allergens may be inhaled, and defects in the skin barrier may also allow allergens to affect the skin. This is not well-studied in cats as compared to dogs.

Symptoms may be minimized by preventing contact with allergens. Keeping cats indoors in air conditioned spaces, bathing, washing bedding frequently, and air filters may help to lessen the effect of common allergens such as pollen or dust mites.

Cats with atopy should have year-round flea prevention treatment to avoid additional damage and inflammation of the skin, even though fleas are not the cause of the atopic allergy.

Atopy is not contagious between animals, since it is due to the specific cat’s sensitivity to allergens.

Atopy is a common skin condition in cats, but may be difficult to differentiate from other skin or allergic conditions, and may coincide.

• Allergen-specific immunotherapy (hyposensitization)
• Steroids
• Cyclosporine
• Antipruritic medication (anti-itch)
• Anti-flea, anti-parasite medication
• Antihistamines
• Antibiotics
• Antifungal