Seasonal Allergies Part 1: Atopy, Etiology and Pathogenesis

Updated: May 20, 2019

Atopy


Atopic dermatitis (AD) is a genetically predisposed, inherited, inflammatory, and itchy skin disease with characteristic clinical features. It is most commonly associated with IgE antibodies to environmental allergens. The expression of typical clinical signs can be seen in dogs and cats with IgE-medicated skin disease, food allergy, or a condition called "atopic-like dermatitis" (ALD). ALD is defined as an itchy skin disease in dogs and cats with characteristic features of atopic dermatitis but negative serum and skin test results for specific pollens, molds, insect proteins, and animal or human dander. Feline atopic dermatitis has many similarities to canine atopic dermatitis.


Etiology and Pathogenesis


The etiology and pathogenesis of Atopic Disease (AD) are complex and involves a genetic predisposition, impairment of the normal barrier function of the skin, and immunologic aberrations. Animals with AD are thought to be genetically predisposed to become sensitized to allergens in the environment. Allergens are proteins that, when inhaled or absorbed through the skin, respiratory tract, or GI tract, evoke allergen-specific IgE production. These allergen-specific IgE molecules affix themselves to tissue mast cells or basophils. When these primed cells come in contact with the specific allergen again, mast cell degranulation results in the release of proteolytic enzymes, histamine, bradykinins, and other vasoactive amines, leading to inflammation (erythema, edema, and pruritus). The skin is the primary target organ in dogs and cats, but rhinitis and asthma can also occur in ~15% of affected animals.


How Does Allergic Skin and Ear Disease Happen?


Pollens that your dog's immune system overreact to, surge and become high in your dog's environment. Your dog's immune system is exposed to these pollens when


- Your dog licks himself and ingests them, then large proteins pass through the "leaky gut" that is inflamed. The intestinal tract is lined with modified skins cells and is home to a large, very important portion of the immune system.

- Your dog breathes the air and his or her respiratory system, also lined with modified skin cells is exposed.

- Your dog walks and rolls around in the grass, and pollens cross through the inflamed, bald, abnormal skin and further exposes the overactive immune system.


Read Part 2: Symptoms of Pollen Allergy and Adverse Food Reactions


Important Action Plan For Skin and Ear Disease Treatment:


Set up your appointment with Dr. Melodie Limpach if you think your pet is suffering from seasonal allergies, other types of allergy, or any skin condition that does not resolve in a couple of weeks. Angelcare Animal Hospital of Racine, WI can usually get your pet in for an exam within 48 hours of your call for help. If finances are limited, we accept Care Credit, Visa, MC, and Discover. We will also design a treatment plan that can work within your budget. The important action plan is to get your pet in sooner than later. The longer your pet is suffering from his skin or ear disease, the longer (and costlier) it will take to produce a happy and healthy pet. Call 262-886-3337 or book now for an appointment today.

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