Atopic Eczema
Summary
Atopic eczema (atopic dermatitis) is a chronic, relapsing inflammatory skin condition characterised by intense pruritus and eczematous lesions. It is the most common chronic skin disease in children, affecting up to 20% of children and 3% of adults. Atopic eczema is part of the "atopic march" alongside asthma and allergic rhinitis. The underlying pathophysiology involves skin barrier dysfunction (often due to filaggrin mutations) and Th2-driven immune dysregulation. Management centres on maintaining skin hydration with emollients, reducing inflammation with topical corticosteroids or calcineurin inhibitors, and avoiding triggers. Severe cases may require systemic immunomodulators or biologics such as dupilumab.
Key Facts
- Prevalence: 15-20% of children; 2-3% of adults
- Age of onset: 60% before 1 year; 90% by age 5
- Atopic triad: Eczema, asthma, allergic rhinitis
- Key gene: Filaggrin (FLG) mutations — major risk factor
- Treatment cornerstone: Emollients + topical corticosteroids
- Life-threatening complication: Eczema herpeticum (HSV superinfection)
Clinical Pearls
"The Itch That Rashes": Eczema pruritus precedes the rash. Scratching causes lichenification. Breaking the itch-scratch cycle is key to management.
Emollients Are Not Optional: Emollients are the foundation of treatment. Patients should use 250-500g per week. Ointments are superior to creams for dry skin.
The Fingertip Unit Rule: One fingertip unit (FTU) = 0.5g; 1 FTU covers two adult palms. Use this to guide topical steroid dosing.
Why This Matters Clinically
Atopic eczema causes significant morbidity including sleep disturbance, psychosocial impact, and reduced quality of life. Uncontrolled eczema increases infection risk and may herald the development of other atopic conditions. Patient education and adherence to treatment are essential.
Incidence & Prevalence
- Children: 15-20% affected
- Adults: 2-3%
- Trend: Increasing prevalence in developed countries
Demographics
| Factor | Details |
|---|---|
| Age | 60% onset before 1 year; majority resolve by adulthood |
| Sex | Slight female predominance in adults |
| Geography | Higher in urban, developed populations |
| Ethnicity | More prevalent and severe in Black children |
Risk Factors
| Factor | Impact |
|---|---|
| Family history of atopy | Strongest risk factor |
| Filaggrin (FLG) mutations | 20-50% of patients |
| Urban living | Associated with higher rates |
| Early antibiotic exposure | Possible association |
| Reduced microbial exposure | "Hygiene hypothesis" |
Mechanism
Step 1: Skin Barrier Dysfunction
- Filaggrin mutations reduce natural moisturising factors
- Impaired lipid synthesis
- Transcutaneous water loss increases
- Allergens and microbes penetrate skin
Step 2: Immune Dysregulation
- Th2-dominant immune response (IL-4, IL-13, IL-31, IL-5)
- IgE overproduction (sensitisation to allergens)
- Eosinophil infiltration
- Mast cell activation
Step 3: Inflammation and Itch
- Cytokines cause pruritus (IL-31 = "itch cytokine")
- Keratinocyte damage
- Epidermal spongiosis
Step 4: Itch-Scratch Cycle
- Scratching damages barrier further
- Lichenification (chronic)
- Increased infection risk
Classification by Age Distribution
| Age | Distribution |
|---|---|
| Infants (less than 2 years) | Face, scalp, extensor surfaces |
| Children (2-12 years) | Flexures (antecubital, popliteal fossae) |
| Adults | Flexures, hands, face, lichenified lesions |
Symptoms
Signs (Acute)
Signs (Chronic)
Associated Features
| Feature | Description |
|---|---|
| Dennie-Morgan folds | Infraorbital creases |
| Hertoghe sign | Thinning of lateral eyebrows |
| Keratosis pilaris | "Chicken skin" on upper arms |
| Anterior neck folds | Horizontal creases |
| White dermographism | White line on stroking skin |
Red Flags
[!CAUTION] Red Flags — Urgent assessment if:
- Punched-out erosions with fever (eczema herpeticum)
- Widespread weeping, crusting, fever (bacterial superinfection)
- Erythroderma (greater than 90% BSA)
- Failure to thrive (infants)
- Severe, treatment-resistant disease
Structured Approach
General:
- Distribution pattern (age-dependent)
- Percentage body surface area (BSA) affected
- Signs of secondary infection
Skin:
- Erythema, oedema
- Vesicles, papules
- Excoriations
- Lichenification (chronic)
- Fissures
Stigmata of Atopy:
- Allergic shiners (periorbital darkening)
- Dennie-Morgan folds
- Cheilitis (lip inflammation)
- Keratosis pilaris
Severity Scoring
| Tool | Description |
|---|---|
| SCORAD | SCORing Atopic Dermatitis (extent, intensity, subjective symptoms) |
| EASI | Eczema Area and Severity Index |
| POEM | Patient-Oriented Eczema Measure (weekly symptoms) |
Clinical Diagnosis
- Diagnosis is clinical; investigations usually not required
- Use UK Working Party criteria or Hanifin & Rajka criteria
UK Working Party Criteria:
- Pruritus (essential) PLUS 3 or more of:
- Onset before 2 years
- History of flexural involvement
- History of dry skin
- Personal history of atopy (or family history in under 4s)
- Visible flexural eczema
Investigations (If Indicated)
| Test | Indication |
|---|---|
| Skin swab | If secondary infection suspected (Staph aureus, HSV) |
| HSV PCR | Suspected eczema herpeticum |
| Serum IgE | Severe atopy, suspected allergic triggers |
| Skin prick tests | Suspected allergic triggers |
| Patch testing | Suspected allergic contact dermatitis |
Management Algorithm
ATOPIC ECZEMA
↓
┌─────────────────────────────────────────┐
│ 1. EMOLLIENTS (Always) │
│ - Use liberally (250-500g/week) │
│ - Ointments > creams for dry skin │
│ - Apply before topical steroids │
└─────────────────────────────────────────┘
↓
┌─────────────────────────────────────────┐
│ 2. TOPICAL CORTICOSTEROIDS │
├─────────────────────────────────────────┤
│ Mild: Hydrocortisone 1% │
│ Moderate: Clobetasone (Eumovate) │
│ Potent: Betamethasone (Betnovate) │
│ Very Potent: Clobetasol (Dermovate) │
│ Use fingertip units; short courses │
└─────────────────────────────────────────┘
↓
┌─────────────────────────────────────────┐
│ 3. SECOND-LINE (If Above Fails) │
├─────────────────────────────────────────┤
│ - Topical calcineurin inhibitors │
│ (Tacrolimus, Pimecrolimus) │
│ - Phototherapy (UVB) │
│ - Wet wraps │
└─────────────────────────────────────────┘
↓
┌─────────────────────────────────────────┐
│ 4. SYSTEMIC (Severe/Refractory) │
├─────────────────────────────────────────┤
│ - Dupilumab (anti-IL-4/IL-13) │
│ - Methotrexate, Ciclosporin │
│ - JAK inhibitors (Baricitinib) │
└─────────────────────────────────────────┘
Emollients
| Type | Characteristics | When to Use |
|---|---|---|
| Ointments | Greasiest, best occlusion | Very dry skin; nighttime |
| Creams | Water-in-oil/oil-in-water | Less dry skin; daytime |
| Lotions | Lightest | Hairy areas; hot weather |
Dosing: 250-500g per week for adults; apply frequently (at least 2-4 times daily)
Topical Corticosteroids
| Potency | Examples | Use |
|---|---|---|
| Mild | Hydrocortisone 1% | Face, infants |
| Moderate | Clobetasone 0.05% (Eumovate) | Mild-moderate, children |
| Potent | Betamethasone 0.1% (Betnovate) | Moderate-severe, body |
| Very potent | Clobetasol 0.05% (Dermovate) | Resistant, thick skin |
Duration: Short bursts (7-14 days); step-down; weekend maintenance for recurrence
Topical Calcineurin Inhibitors
| Drug | Notes |
|---|---|
| Tacrolimus 0.03%, 0.1% | Potent; face, eyelids; transient stinging |
| Pimecrolimus 1% | Mild-moderate eczema |
- Indication: Steroid-sparing, face/eyelid eczema, second-line
- Blackbox warning: Theoretical cancer risk (not confirmed in long-term data)
Systemic Therapy
| Drug | Indication | Notes |
|---|---|---|
| Dupilumab | Moderate-severe | Anti-IL-4/IL-13 biologic; self-injection; very effective |
| Ciclosporin | Severe | Rapid onset; nephrotoxicity |
| Methotrexate | Moderate-severe | Slow onset; hepatotoxicity |
| Azathioprine | Moderate-severe | Check TPMT |
| JAK inhibitors | Moderate-severe | Baricitinib, upadacitinib |
Managing Complications
| Complication | Treatment |
|---|---|
| Bacterial infection | Flucloxacillin; antiseptic wash |
| Eczema herpeticum | IV aciclovir; dermatology admission |
| Sleep disturbance | Sedating antihistamines (short-term) |
Trigger Avoidance
- Avoid soap and irritants (use soap substitutes)
- Cotton clothing
- Keep fingernails short
- Environmental allergens (if clearly implicated)
Immediate
| Complication | Features | Management |
|---|---|---|
| Secondary bacterial infection | Crusting, weeping, fever | Flucloxacillin, antiseptics |
| Eczema herpeticum | Punched-out erosions, fever, malaise | IV aciclovir, admission |
Chronic
| Complication | Notes |
|---|---|
| Lichenification | Chronic scratching |
| Dyspigmentation | Post-inflammatory |
| Eye complications | Keratoconjunctivitis, cataracts |
| Psychosocial | Anxiety, depression, low self-esteem |
| Sleep disturbance | Pruritus at night |
Natural History
| Age | Outcome |
|---|---|
| Childhood | Most improve or resolve by adolescence |
| Adulthood | 10-30% persist; may relapse |
| Atopic march | Eczema → asthma → allergic rhinitis |
Prognostic Factors
| Good Prognosis | Poor Prognosis |
|---|---|
| Early onset (infancy) | Severe early disease |
| Mild severity | Multiple atopic conditions |
| No FLG mutations | FLG mutations |
| Good treatment adherence | Late onset (adulthood) |
Key Guidelines
- NICE NG169: Atopic eczema in under 12s (2021) — UK standard.
- NICE CG57: Atopic eczema in children (updated).
- AAD Guidelines on Atopic Dermatitis (2014) — American Academy of Dermatology.
- EADV Guidelines on Atopic Eczema — European.
Landmark Trials
SOLO 1 & 2 (2016) — Dupilumab for atopic dermatitis
- Key finding: Dupilumab significantly improved EASI scores and pruritus vs placebo
- Clinical Impact: First biologic approved for eczema
- PMID: 27690741
BREEZE-AD Trials (2020) — JAK inhibitors
- Key finding: Baricitinib effective for moderate-severe AD
- PMID: 32109266
Evidence Strength
| Intervention | Level | Key Evidence |
|---|---|---|
| Emollients | 1a | Cochrane review |
| Topical corticosteroids | 1a | Multiple RCTs |
| Dupilumab | 1b | SOLO 1 & 2 |
| Tacrolimus | 1a | Cochrane review |
What is Atopic Eczema?
Atopic eczema (often just called eczema) is a very common skin condition that causes dry, itchy, inflamed skin. It often runs in families and is linked with asthma and hay fever.
Why does it happen?
The skin's protective barrier is weaker than normal, so it loses moisture and lets irritants in. The immune system then overreacts, causing redness and itching.
How is it treated?
- Moisturisers (emollients): The most important treatment. Use lots (a big pot every 1-2 weeks), and apply frequently.
- Steroid creams: Reduce redness and itching during flare-ups. Use as directed by your doctor.
- Avoid triggers: Soap, bubble bath, wool clothing, overheating.
- Stronger treatments: For severe eczema, doctors may prescribe tablets or injections.
What to expect
- Most children improve as they get older
- Eczema can come and go throughout life
- Good skincare habits help control symptoms
When to seek help
See a doctor urgently if:
- There are painful, weepy areas with fever (may be infected)
- There are clusters of small blisters that look "punched out" (eczema herpeticum — needs urgent treatment)
- Eczema is not improving despite treatment
Primary Guidelines
- National Institute for Health and Care Excellence (NICE). Atopic eczema in under 12s: diagnosis and management (NG169). 2021. nice.org.uk/guidance/ng169
Key Trials
- Simpson EL, et al. Two Phase 3 Trials of Dupilumab versus Placebo in Atopic Dermatitis (SOLO 1 and SOLO 2). N Engl J Med. 2016;375(24):2335-2348. PMID: 27690741
- van Zuuren EJ, et al. Emollients and moisturisers for eczema. Cochrane Database Syst Rev. 2017. PMID: 28166390
Further Resources
- National Eczema Society: eczema.org
- British Association of Dermatologists: bad.org.uk
Last Reviewed: 2025-12-24 | MedVellum Editorial Team
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. Clinical decisions should account for individual patient circumstances. Always consult appropriate specialists.