What are the symptoms of atopic dermatitis?

Symptoms of atopic dermatitis vary from person to person. The most common symptoms are:

• Dry, itchy skin
• Cracks behind the ears
• Rashes on the cheeks, arms, and legs

The itchy feeling is an important factor in atopic dermatitis, because scratching and rubbing in response to itching worsen the skin inflammation characteristic of this disease. People with atopic dermatitis seem to be more sensitive to itching and feel the need to scratch longer in response. They develop what is referred to as " the itch-scratch cycle ": The extreme itchiness of the skin causes the person to scratch, which in turn worsens the itch, and so on. Itching is particularly a problem during sleep, when conscious control of scratching decreases and the absence of other outside stimuli makes the itchiness more noticeable.

Scaling or leathery skin

The way the skin is affected by atopic dermatitis can be changed by patterns of scratching and resulting skin infections. Some people with the disease develop red, scaling skin where the immune system in the skin is becoming very activated. Others develop thick and leathery skin as a result of constant scratching and rubbing. This condition is called lichenification .

Papules and excoriations

Still others develop papules, or small raised bumps, on their skin. When the papules are scratched, they may open (excoriations) and become crusty and infected. These conditions can also be found in people without atopic dermatitis or with other types of skin disorders.

Changes in skin around the eyes

Atopic dermatitis may also affect the skin around the eyes, the eyelids, and the eyebrows and lashes. Scratching and rubbing the eye area can cause the skin to change in appearance. Some people with atopic dermatitis develop an extra fold of skin under their eyes, called an atopic pleat or Dennie-Morgan fold. Other people may have hyperpigmented eyelids, meaning that the skin on their eyelids darkens from inflammation or hay fever (allergic shiners). Patchy eyebrows and eyelashes may also result from scratching or rubbing.

Differences noted in skin of eczema patients

Researchers have noted differences in the skin of people with atopic dermatitis that may contribute to the symptoms of the disease. The epidermis , which is the outermost layer of skin, is divided into two parts:

• The inner part contains moist, living cells.
• The outer part, known as the horny layer or stratum corneum , contains dry, flattened, dead cells.

Under normal conditions the stratum corneum acts as a barrier. It keeps the rest of the skin from drying out and protects other layers of skin from damage caused by irritants and infections. When this barrier is damaged, irritants act more intensely on the skin. The skin of a person with atopic dermatitis loses too much moisture from the epidermal layer. This allows the skin to become very dry and reduces its protective abilities. In addition, the patient's skin is very susceptible to recurring infections, such as:

• Staphylococcal and streptococcal bacterial skin infections
• Warts
• Herpes simplex
• Molluscum contagiosum (skin disorders caused by a viruses)

Skin features of atopic dermatitis

* Lichenification : thick, leathery skin resulting from constant scratching and rubbing

* Papules : small raised bumps that may open when scratched, becoming crusty and infected

* Ichthyosis: dry, rectangular scales on the skin

* Keratosis pilaris: small, rough bumps, generally on the face, upper arms, and thighs

* Hyperlinear palms: increased number of skin creases on the palms

* Urticaria: hives (red, raised bumps), often after exposure to an allergen, at the beginning of flares, or after exercise or a hot bath

* Cheilitis: inflammation of the skin on and around the lips

* Atopic pleat (Dennie-Morgan fold): an extra fold of skin that develops under the eye

* Hyperpigmented eyelids: eyelids that have become darker in color from inflammation or hay fever