Atopic Dermatitis: Clinical Overview and Management Guide

Atopic Dermatitis (Eczema): Clinical Overview

Pathophysiology, Diagnosis, and Management Protocols

For Medical Students & Clinicians

Prevalence: A Global Burden

Atopic Dermatitis is the most common chronic inflammatory skin disease, predominantly affecting the pediatric population.

60% of cases develop within the first year of life.

Associated with the 'Atopic March': Eczema → Food Allergy → Asthma → Rhinitis.

Pathophysiology: The Barrier Defect

Filaggrin Mutation: Loss of structural protein leading to defective stratum corneum.

Transepidermal Water Loss (TEWL): Increased moisture evaporation causes xerosis.

Immune Dysregulation: Th2 pathway dominance (IL-4, IL-13) drives inflammation.

Clinical Presentation by Age

Infants

Extensor surfaces, face (cheeks), and scalp. Diaper area usually spared.

Children

Flexural folds (antecubital/popliteal fossae), neck, wrists.

Adults

Flexural areas, hands, face (eyelids), and nipples. Lichenification is common.

Common Triggers & Exacerbating Factors

Aeroallergens: Dust mites, pet dander, pollens.

Irritants: Wool, synthetic fabrics, harsh soaps, detergents.

Psychological: Stress and anxiety (triggers neuro-immune flare).

Environment: Extreme heat, humidity shifts, or dry cold air.

Daily Management: The Foundation

Aggressive Emollients

Apply thick creams/ointments (not lotions) at least twice daily. 'Soak and seal' method immediately after bathing.

Bathing Routine

Short (5-10 min), warm (not hot) baths. Use soap-free cleansers. Avoid scrubbing.

Pharmacological Management Ladder

Mild Disease

Low-potency TCS (e.g., Hydrocortisone 1-2.5%) for face/folds. Reactive therapy.

Moderate Disease

Medium-potency TCS (e.g., Triamcinolone). TCIs (Tacrolimus) for steroid-sparing. Proactive (weekend) therapy.

Severe/Refractory

High-potency TCS (short term). Phototherapy. Systemics: Dupilumab (Biologic), JAK Inhibitors, Cyclosporine.

Topical Corticosteroid Potency (USA Classification)

Class I (Super Potent)

Clobetasol propionate 0.05%

Class II-III (High Potency)

Betamethasone dipropionate 0.05%, Fluocinonide

Class IV-V (Mid Potency)

Triamcinolone acetonide 0.1%

Class VI-VII (Low Potency)

Desonide 0.05%, Hydrocortisone 1-2.5%

Dosing Rule: 1 Fingertip Unit (FTU) = ~0.5g = treats area of 2 adult palms.

Red Flags & Complications

1. Infection (S. aureus)

Weeping, honey-colored crusts (Impetiginization), pustules. Requires topical mupirocin or systemic antibiotics.

2. Eczema Herpeticum

EMERGENCY. Disseminated HSV infection. Monomorphic punched-out erosions, vesicles. Requires immediate Acyclovir.

Clinical Takeaways

Education is Key: Demonstrate 'Squeaky' vs 'Greasy' moisturizer application to parents.

Steroid Phobia: Address barely; undertreatment leads to chronic lichenification.

Maintenance: Proactive intermittent biologic/TCS use prevents relapse effectively.