What is atopic dermatitis in dogs?

Common disease that affects about 10% of dogs, close to eczema in humans. Atopic dermatitis is a chronic inflammation of the skin, of genetic origin. It appears in dogs generally before the age of 3 years.

Atopic dermatitis evolves over time but persists throughout the life of the dog. A dog with canine atopic dermatitis may have one or more of these signs:

• Dry skin
• Red and inflammatory lesions
• Itches
• Sometimes ‘pimples’, pustules, oozing and thickening of the skin
• Mainly located on the belly, in large folds (ars, armpits), between the fingers (palmar), on the face and the ears (pavilions)

Atopic dermatitis evolves by outbreaks, with periods of crises and periods of lull.

A skin barrier disorder:

• Normal skin: the water evaporates little, allergens cannot enter.

The superficial part of the skin behaves like a protective brick wall. The bricks are cells and the mortar is composed of lipids that provide good impermeability. This prevents dehydration and the penetration of external agents.

• Atopic skin: water evaporates, allergens can enter.

The skin does not play its protective role: it allows the evaporation of too much water, which is responsible for skin dryness. It allows allergens and microbes to enter more easily, which is responsible for inflammatory reactions.

*Allergen: substance capable of triggering an allergic reaction