Eczema, also known as Atopic Dermatitis (AD), is a chronic inflammatory skin condition affecting millions of people worldwide. It is characterized by intense itching (pruritus) and a recurring rash that cycles through flare-ups and periods of remission. This condition involves a compromised skin barrier and an overactive immune response that triggers inflammation. The appearance and affected areas of Atopic Dermatitis change significantly as a person ages, leading to its categorization into distinct phases.
The Infantile Phase
The initial presentation of Atopic Dermatitis typically occurs between birth and two years of age, with onset often around three to six months old. This phase is characterized by acute lesions that appear red, raised, and often “weepy” or crusted due to fluid leaking from the inflamed skin. The intense itching leads infants to rub the affected areas.
The rash location is highly specific, involving the face, particularly the cheeks and scalp, and the extensor surfaces of the limbs, such as the outside of the elbows and knees. The diaper area is usually spared from the rash.
The skin is generally more exudative, characterized by moist, raw areas and crust formation resulting from acute inflammation and mechanical damage. This infantile pattern often indicates a developing atopic tendency.
The Childhood Phase
The presentation shifts notably when a child enters the phase spanning from two years of age until puberty, often extending to about twelve years old. The location of the rash moves away from the extensor surfaces to primarily involve the flexural surfaces. This means the rash is predominantly found in the skin creases, most commonly the insides of the elbows (antecubital fossae) and behind the knees (popliteal fossae).
The appearance of the lesions changes significantly from earlier weeping patches to a more chronic, thickened state. The skin becomes dry, scaly, and develops a leathery texture with exaggerated skin markings, a process known as lichenification. This thickening is a direct consequence of chronic scratching and rubbing.
Other common sites for the childhood rash include the wrists, ankles, and neck. This pattern of involvement, centered on the major flexural folds, is considered the textbook presentation of Atopic Dermatitis.
Adolescent and Adult Manifestations
In adolescence and adulthood, Atopic Dermatitis often becomes more localized, though it can remain severe in the affected areas. While flexural areas from childhood may still be involved, the rash is more likely to present as thick, persistent plaques of lichenification. New, specific areas of involvement become common during this life stage.
Adults frequently experience chronic hand eczema, which can be debilitating due to frequent exposure to irritants and water. The hands and feet, including the palms and soles, often develop dry, scaly, and fissured patches. The face and neck are also commonly involved, sometimes presenting as dermatitis around the mouth or persistent eyelid inflammation.
Adult lesions are less likely to be acutely red and weeping, instead appearing as hyperpigmented, thickened plaques that reflect the long-standing nature of the inflammation. The skin retains a tendency toward dryness (xerosis), and the intense itch continues to drive the cycle of scratching.