Eczema is the common name given to Atopic Dermatitis, a chronic inflammatory skin condition that typically begins in the first few years of life. It is the most widespread skin disease of infancy and childhood1 and is often the initial indication that a child will develop further allergic conditions such as allergic rhinitis and allergic asthmaHthe beginning of the soHcalled “atopic march.”2. It was once thought of as solely a disease of childhood, but is becoming increasingly prevalent in all age groups. Although it does sometimes begin and resolve itself during childhood, it can progress into adulthood, or simply have a later onset for some individuals. There have been many significant scientific discoveries in recent years about the causes of eczema including the discovery of the filaggrin gene and the loss of barrier function, and also the current understanding of the role of the mast cell in allergic reaction. In addition, there have been highly credible theories as to what serves as the catalyst for the disease, including the hygiene hypothesis and the misuse of topical steroids.
Atopic dermatitis is characterized cracked or scaly skin, discolored patches, erythema (red skin), papules, exudate (oozing), and intense pruritus (itching), which can secondarily cause insomnia and diminished quality of life. It may present differently, combining any of these symptoms, depending on the age and nature of the patient, as well as the stage of the disease. Eczema is usually classified in three distinct stages: infancy, childhood, and adolescent/adulthood. Beginning in the second or third month of life, it often appears as patches on the cheeks referred to as “milk crust” and later in the flexures of the arms and legs. It is reminiscent of seborrheic dermatitis, also known as “cradle cap.” At this point, the condition may or may not yet have developed into an atopic condition3.
As the disease progresses into childhood, the eczematous lesions can be found on the flexural areas such as the innerHelbow, neck, and wrists. Even if the disease does resolve itself during adolescence, abnormal dryness and lichenification may remain in the affected areas. Although about 60% of the childhood cases of eczema will disappear completely4, it frequently persists into adulthood. It can also develop for the first time at this later stage. The areas classically affected during this period are the flexures as well as the orbital and perioral regions of the head and most appear as dry, lichenified plaques5.
The psychological effects of eczema must be considered as well for both children and adults. Living with atopic dermatitis can have a profoundly negative effect on quality of life. Constant itching and scratching, soreness, pain, and discomfort can lead to high stress levels and sleep deprivation. Lifestyle may be affected, as the patient’s activities might be restricted. Depression is also a concern as the patient might begin to feel hopelessness, embarrassment, despair due to the chronic nature of the disease6.
The specific definition of atopic dermatitis should be mentioned as the term “eczema” is often separated into two separate categories: atopic (extrinsic) dermatitis and atopiform (intrinsic) dermatitis; or in other words, allergic eczema and nonHallergic eczema, respectively. According to the World Allergy Organization (WAO), atopy and atopic conditions are defined only in association with IgEHmediated pathophysiology7. This pertains to the body’s ability to create the allergic antibody in response to an antigen. By exclusion, this would signify that only atopic dermatitis is specifically allergyHinduced eczema. There is some debate over whether there are indeed two distinct forms; it is postulated by some that non IgEHassociated eczema may represent a transitional phase of the IgEHassociated form in infancy8. At the stage when an infant or child contacts the earliest signs of eczema, in about half the cases, there is no evidence of IgEHmediated sensitization9. These patients are not yet technically considered “atopic” but could progress into allergic sensitization.
What provokes the disease to progress from a nonHallergic condition to an allergic one and potentially pushes the patient to develop other atopic diseases such as asthma and hay fever? The etiology of eczema isn’t entirely clear. However, there is considerable research as to what causes it to manifest and several theories have been produced as a result. Most certainly, it is a multifactorial condition that occurs due to both genetic and environmental factors10.