Eczema is a general term used to describe a family of skin conditions associated with dry, irritated, itchy skin that can be chronic. There are many different forms of eczema, and it is one of the most common conditions that dermatologists encounter in practice. Eczema can’t be cured, but it can be controlled. Here we will discuss atopic dermatitis, the most common form of eczema.
Atopic dermatitis (AD) is familial, but not contagious: people with AD cannot give the disease to someone else. Those patients with the most severe symptoms are very likely to have close relatives with eczema, too.
Eczema has been described as “the itch that rashes”: scratching the itch worsens the rash and its “itchiness”. The “itch/scratch/itch” cycle must be broken for eczema patients to gain comfort. Scratching can lead to redness, swelling, weeping, crusting, and scaling. Scratching leads to thickened skin; markings may remain on skin that has been rubbed or scratched. Commonly affected skin areas include the inside of the arms, back of the knees, wrists, and the cheeks.
- Between 10% and 20% of people worldwide develop atopic dermatitis.
- 90% of people with eczema develop symptoms prior to age 5.
- There is a close association of eczema with hay fever and asthma that occur in families and individuals. Recent research has shown that about 30% of cases of adult allergic asthma is associated with childhood eczema and hay fever.
- Most children “outgrow” atopic dermatitis during adolescence.
- Patients with atopic dermatitis are a much higher risk group for the development of food allergies.
If you have a genetic predisposition for atopic eczema, you may not develop symptoms until responding to one or more environmental factors.
Triggers for a flare of eczema include:
- contact irritants include soaps, detergents, fragrances, nickel (found in jewelry), formaldehyde (personal hygiene products, clothing), and cocamidopropyl betaine (found in shampoo, soap, toothpaste).
- winter dryness or summer humidity may flare eczema and exacerbate itching.
- emotional stress can lead to a flare and itching of the skin.
- heat and sweating can lead to the itch which causes patients to scratch.
- infections from bacteria or others like molluscum, herpes, or fungus can all lead to a flare of atopic dermatitis.
- allergic reactions to food or an environmental substance (such as pollen) can trigger eczema.
Other forms of eczema:
- Keratosis Pilaris is a hereditary skin condition associated with small bumps on the skin localized to the upper arms, anterior thighs, and commonly on the cheeks. In adolescence, these bumps may be mistaken for acne.
- Hand eczema can present as itchy, scaly patches on the hands that can become red, cracked, and painful leading to infection.
- Allergic contact dermatitis: specifically related to contact with external substances (e.g. poison ivy)
- Dry skin: causes and remedies for dry skin
All types of eczema cause itching and redness and some will blister, weep, and scale.