Overview
Definition
A chronic, highly pruritic inflammatory skin disease associated with epidermal barrier dysfunction and immune dysregulation.
Epidemiology
Very common in children (up to 20%), often resolving or improving by adulthood. Part of the 'Atopic March' (Eczema -> Food Allergy -> Asthma -> Allergic Rhinitis).
Etiology & Risk Factors
- Filaggrin gene (FLG) mutations leading to a defective skin barrier (allowing water loss and allergen entry).
- Th2-skewed immune response (IgE mediated).
Clinical Symptoms
- Intense pruritus ('the itch that rashes')
- Infants: Erythematous, weeping patches on the face/cheeks and extensor surfaces
- Children/Adults: Lichenified (thickened), dry plaques on flexural surfaces (antecubital and popliteal fossae)
Clinical Approach
Diagnosis
- Clinical diagnosis based on history and physical exam
- Often associated with elevated IgE levels and peripheral eosinophilia (though not required for diagnosis)
Management
- Basic Skincare: Frequent application of thick emollients/ointments (e.g., Vaseline) immediately after bathing
- Trigger avoidance (harsh soaps, specific allergens, dry air)
- Acute flares: Topical Corticosteroids (lowest effective potency)
- Maintenance/Steroid-sparing: Topical Calcineurin Inhibitors (Tacrolimus)
- Severe/Refractory: Dupilumab (Anti-IL-4 receptor monoclonal antibody)
Complications
- Secondary bacterial infections (Staphylococcus aureus, causing honey-colored crusts/impetigo)
- Eczema Herpeticum (life-threatening disseminated Herpes Simplex Virus infection on eczematous skin)