Key Facts

Atopic eczema (atopic dermatitis) is a chronic inflammatory skin condition that significantly impacts quality of life for children and their families. It is characterised by periods of flare and remission, with the majority of children improving by adulthood.

Epidemiology

Affects up to 20% of UK children and 1-3% of adults. Onset is before age 1 in ~60% and before age 5 in ~90%. Prevalence has tripled over the past 30 years. More common in developed countries ('hygiene hypothesis'). Equal sex distribution. Associated with Afro-Caribbean ethnicity in the UK.

Aetiology

• Genetic: FLG (filaggrin) mutations in ~30% — loss of epidermal barrier protein; strong family history of atopy
• Immune dysregulation: Th2-skewed immune response → IgE overproduction, eosinophilia
• Environmental triggers: Soap/detergents, wool/synthetic fabrics, heat/sweating, pet dander, house dust mite, food allergens (egg, cow's milk in young children), infection

Pathophysiology

Impaired skin barrier (filaggrin deficiency) → increased transepidermal water loss and allergen/irritant penetration → Th2 immune activation → IL-4, IL-13, IL-31 release → inflammation, pruritus, and IgE production. Scratching causes further barrier damage (itch-scratch cycle). Skin is colonised with Staphylococcus aureus in ~90% of eczema patients, which acts as a superantigen and exacerbates inflammation.

Distribution by Age

• Infants (<2 years): Face (cheeks), scalp, extensor surfaces (spares nappy area)
• Older children (>2 years): Flexural (antecubital, popliteal fossae), wrists, ankles, neck
• All ages: Hands, periorbital

Morphology

• Acute: Erythema, vesicles, weeping, crusting
• Subacute: Erythema, scaling, excoriations
• Chronic: Lichenification (thickened, leathery skin), hyperpigmentation/hypopigmentation, fissuring

Severity Assessment (NICE NG190)

• Mild: Areas of dry skin, infrequent itching, no impact on daily activities
• Moderate: Areas of dry skin, frequent itching, redness, moderate impact on daily activities and sleep
• Severe: Widespread areas, incessant itching, bleeding/oozing/cracking, significant impact on daily activities and sleep

Red Flags

• Eczema herpeticum: Widespread, painful, monomorphic vesicles/punched-out erosions, often with fever — HSV infection; emergency treatment required
• Secondary bacterial infection: Crusting, weeping, pustules, systemic symptoms — Staph aureus or Strep pyogenes
• Faltering growth with severe eczema — consider food allergy assessment
• Eczema not responding to treatment — reconsider diagnosis, check compliance, consider allergy testing

Bedside

• Clinical examination: Distribution, morphology, severity assessment
• Eczema severity scoring: EASI (Eczema Area and Severity Index), SCORAD, or POEM (Patient-Oriented Eczema Measure)
• Growth assessment: Plot height and weight if severe eczema or dietary restrictions

Bloods

• Not routinely required — eczema is a clinical diagnosis
• Specific IgE / skin prick testing: Only if suspected food allergy (immediate reactions) — egg, cow's milk, peanut, wheat, soy, fish most common in young children
• Total IgE: Often elevated but non-specific; not routinely helpful
• FBC: Eosinophilia may be present (non-specific)

Imaging

• Not applicable

Special Tests

• Patch testing: If contact allergic dermatitis suspected (dermatology referral)
• Skin swab MC&S: If secondary infection suspected — identify organism and sensitivities
• Food allergy testing: If consistent history of immediate-type reactions or severe eczema not responding to optimal treatment (refer to allergy specialist)

Non-pharmacological

• Emollients: Cornerstone of management — apply generously 3-4 times daily and after bathing; 250-500g per week for child; choose a preparation the child will accept (cream, ointment, lotion)
• Avoid triggers: Soap-free wash products, avoid biological detergents, cotton clothing, keep nails short, cool environment
• Wet wraps: For moderate-severe flares — emollient ± dilute steroid under wet bandages; done under specialist guidance
• Bath emollients: Added to bath water (though evidence debated — BATHE RCT 2018 showed limited additional benefit)

Pharmacological

• Topical corticosteroids (step-up/step-down approach):
  • Mild: Hydrocortisone 1% OD-BD (face, flexures)
  • Moderate: Clobetasone butyrate 0.05% (Eumovate) OD-BD
  • Potent: Mometasone furoate 0.1% or betamethasone valerate 0.1% OD (body/limbs for moderate-severe flares)
  • Use for short courses (7-14 days) during flares; proactive maintenance therapy (e.g., 2 days per week) reduces relapse
• Topical calcineurin inhibitors (NICE TA82): Tacrolimus 0.03% ointment (children ≥2) or pimecrolimus 1% cream for face/flexures, steroid-resistant areas, or steroid phobia; does not cause skin atrophy
• Antihistamines: Sedating (chlorphenamine 1mg/kg nocte) ONLY for sleep disturbance — non-sedating antihistamines have no evidence for itch in eczema
• Antibiotics: Flucloxacillin 12.5-25mg/kg QDS for 7 days for clinically infected eczema (if widespread); topical fusidic acid for localised infection (max 2 weeks to avoid resistance)
• Eczema herpeticum: IV aciclovir 10mg/kg TDS for 5-7 days (oral if mild — 400mg 5×/day)
• Systemic immunosuppression (severe refractory — specialist only): Ciclosporin 2.5-5mg/kg/day, methotrexate 0.2-0.7mg/kg/week, azathioprine, mycophenolate
• Dupilumab (anti-IL-4/IL-13): NICE TA681 for moderate-severe eczema in ≥6 years not controlled by topical therapy; given SC every 2-4 weeks

Surgical/Interventional

• Not applicable

Referral Criteria

• Moderate-severe eczema not responding to optimised topical therapy — dermatology
• Suspected eczema herpeticum — emergency admission
• Suspected food allergy — allergy specialist
• Significant psychological impact — psychology/CAMHS
• Need for systemic therapy — specialist dermatology

• Natural history: ~60-70% of children with eczema are clear or significantly improved by adolescence
• Persistent disease: ~10-15% continue to have significant eczema into adulthood
• Atopic march: ~30% develop asthma, ~35% develop allergic rhinitis
• Quality of life: Eczema has a greater impact on quality of life than many other chronic childhood conditions
• Psychological: Increased rates of anxiety, depression, sleep disturbance, and bullying
• Skin infections: Recurrent flares with secondary infection common; eczema herpeticum rare but potentially serious

Topical Corticosteroid Potency Ladder

Fingertip Units (FTU) Dosing Guide