Healthy skin is smooth, hydrated, and elastic, with an even tone and a protective barrier to prevent damage. It has three layers: the epidermis (outer layer), the dermis (middle layer with collagen and blood vessels), and the hypodermis (fat and tissue that cushion, insulate, and connect skin to the body). A healthy epidermis retains moisture and blocks irritants. Recognizing healthy skin can help you spot signs of atopic dermatitis—like dryness, itching, and inflammation—and take steps to protect your skin.

In mild atopic dermatitis, the skin's outermost layer, the epidermis, becomes dry, rough, and slightly discolored, often appearing as red, dark brown, purple, or ashen gray patches depending on skin tone. The skin barrier, composed of lipids and proteins, is weakened, allowing moisture to escape and irritants to enter. Itching is mild but persistent. This stage doesn’t cause significant inflammation but the skin may be more sensitive to irritants.

The epidermis shows more pronounced inflammation at this stage with noticeable discoloration, swelling, and scaling. The skin’s protective barrier becomes more compromised, leading to dryness and visible cracking. More areas of the skin, including the head, hands, and larger body regions, may be affected. Scratching exacerbates the condition, causing further damage to the skin's integrity. The skin's ability to retain moisture is reduced, and localized infections can sometimes occur if the skin is broken.

In severe atopic dermatitis, the outer layer becomes extremely dry, thickened, and cracked, which weakens the skin's barrier even further. Heightened inflammation and increased blood flow contribute to deep redness and swelling. Persistent itching, constant scratching, and open sores can lead to infection, causing the skin to become painful, crusted, and even oozing. At this stage, the skin’s protective function is severely impaired, impacting overall skin health and quality of life.