Updated: Oct 6, 2018
Atopic dermatitis (AD) is a chronic skin condition characterized by dry, itchy skin. AD is often referred to as eczema, a word that refers to a broader group of skin conditions. "Dermatitis" refers to a condition of the skin and "atopic" relates to diseases caused by allergic reactions. As an atopic disease, AD is in the same classification as hay fever and asthma.
In atopic dermatitis, the skin becomes extremely itchy and inflamed, causing redness, swelling, vesicle formation, cracking, weeping, crusting, and scaling. In addition, dry skin is a very common complaint in almost all those afflicted with atopic dermatitis.
Although atopic dermatitis can occur in any age, most often it affects infants and young children. Occasionally, it may persist into adulthood or may rarely appear at that time. Some patients tend to have a protracted course with ups and downs. In most cases, there are periods of time when the disease is worse, called exacerbations or flares, which are followed by periods when the skin improves or clears up entirely, called remissions. Many children with atopic dermatitis enter into a permanent remission of the disease when they get older, although their skin may remain somewhat dry and easily irritated.
Multiple factors can trigger or worsen atopic dermatitis, including low humidity, seasonal allegies, exposure to harsh soaps and detergents, and cold weather. Environmental factors can activate symptoms of atopic dermatitis at any time in the lives of individuals who have inherited the atopic disease trait.
Symptoms of Atopic Dermatitis
The primary symptom of AD is dry, itchy skin that often turns into a red rash. During a flare, AD becomes a red, itchy rash. Many different physical and internal factors can trigger an eczema flare-up. The resulting inflammation causes increased blood flow and the urge to itch. Eczema flares are part of the agonizing itch-scratch cycle. It’s hard to fight the physical and psychological components that drive the itch-scratch cycle. Scratching feels good at the time but can lead to more inflammation and even skin infections.
Cause of Atopic Dermatitis
The cause of atopic dermatitis is not known, but the disease seems to result from a combination of genetic (hereditary) and environmental factors. There seems to be a basic cutaneous hypersensitivity and an increased tendency toward itching. Evidence suggests that the disease is associated with other so-called atopic disorders such as hay fever (seasonal allergies) and asthma, which many people with atopic dermatitis also have. In addition, many children who outgrow the symptoms of atopic dermatitis go on to develop hay fever or asthma. Although one disorder does not necessarily cause another, they may be related, thereby giving researchers clues to understanding atopic dermatitis. Many of those affected seem to have either a decreased quantity of or a defective form of a protein called filaggrin in their skin. This protein seem to be important in maintaining normal cutaneous hydration. It is important to understand that food sensitivities do not seem to be a major inciting factor for most cases of atopic dermatitis. This is an area of active research. Patients with atopic dermatitis seem to have mild immune system weakness. They are predisposed to develop fungal foot disease and cutaneous staphylococcal infections, and they can disseminate herpes simplex lip infections (eczema herpeticum) and smallpox vaccination (eczema vaccinatum) to large areas of skin.