What is Atopic Eczema?
Atopic eczema (also called atopic dermatitis or simply eczema) is a chronic, relapsing inflammatory skin disease characterized by intensely itchy rashes, disrupted skin barrier function, and typically begins in early childhood. 1
Core Definition
Atopic eczema is a chronic, pruritic inflammatory skin condition that most commonly starts between 3-6 months of age, with 60% of cases developing in the first year of life and 90% by age 5 1. The terms "atopic eczema" and "atopic dermatitis" are synonymous and interchangeable 1.
Key Clinical Features
The disease presents with several hallmark characteristics:
- Intense pruritus (itching) - This is the defining symptom that drives much of the disease burden and creates a self-perpetuating itch-scratch cycle 2
- Visible skin changes including erythema (redness), edema (swelling), xerosis (dry skin), erosions/excoriations (scratches), oozing and crusting, and lichenification (thickened skin from chronic scratching) 1
- Age-dependent distribution patterns - The appearance and location of rashes vary by patient age and how long lesions have been present 1
Pathophysiology
Atopic eczema arises from a complex interaction of three main factors 1, 3:
- Genetic mutations - particularly in filaggrin, a key protein for skin barrier function
- Immune dysregulation - often associated with elevated IgE levels and Th2-mediated inflammation
- Environmental triggers - that disrupt the already compromised epidermal barrier
Associated Conditions
The disease frequently occurs alongside other atopic conditions, with patients often having a personal or family history of 1:
- Type I allergies
- Allergic rhinitis (hay fever)
- Asthma
Natural History
While 70-90% of affected children see resolution by adulthood, 10-30% continue to have disease into adult years, and a small percentage first develop symptoms as adults 1. The condition follows a relapsing-remitting course with periods of flares and improvement 2.
Diagnosis
The diagnosis is made clinically based on history, morphology, and distribution of skin lesions - no laboratory tests are required 1. The American Academy of Dermatology has established simplified diagnostic criteria based on symptoms and physical examination findings 2.