Background

Note: The terms atopic dermatitis and eczema are used interchangeably in this document and refer to chronically itchy and inflamed skin, which may be accompanied by hay fever and/or asthma.

Atopic dermatitis is a chronic and relapsing dermatitis that typically shows up during infancy or early childhood.  It affects 5%-20% of the childhood population around the world.  Atopic dermatitis appears increasingly common and is more prevalent in developed countries and in urban locations.  Eczema is grouped into three age categories: infantile, childhood, and adult. In infants, the face and extensors are typically involved.  Childhood and adult eczema tends to affect the flexural areas and is characterized by more chronic inflammation with dry, scaly, thickened skin.  People with eczema typically have a lower tolerance for skin irritants.  Heat and perspiration are the most common offenders with wool and emotional stress close behind.

There are many factors at play in the development of eczema.  Family history (especially maternal history) is a strong predictive risk factor, but there appear to be many environmental factors as well, including insufficient exposure to microorganisms in early childhood and excessive exposure to airborne pollution.^1,2  People with eczema have problems with their skin barrier, which puts them at risk for increased evaporation of moisture from the skin and decreased ability to maintain skin moisture.  They also have an increased risk of developing skin infections due to bacteria, viruses, and fungus.  The superficial cutaneous nervous system in people who have atopic dermatitis is hyper-reactive as well, and people with atopic dermatitis are more likely to experience the sensation of itch.