Key Facts

Atopic eczema (atopic dermatitis) is a chronic, relapsing inflammatory skin condition characterised by dry, itchy skin. It is the most common skin condition in children and often improves with age. A stepwise approach to management is recommended.

Epidemiology

• Affects 15-20% of children and 5-10% of adults in the UK
• Onset before age 5 in 90% of cases; before age 1 in 60%
• 60-70% of childhood eczema resolves by adolescence
• Part of the atopic triad: eczema, asthma, allergic rhinitis (atopic march)

Aetiology

• Genetic: filaggrin (FLG) gene mutations (20-30% of eczema patients; filaggrin is essential for skin barrier function)
• Immune dysregulation: Th2 predominant immune response with elevated IgE
• Environmental triggers: house dust mite, pet dander, pollen, irritants (soaps, detergents, wool), temperature changes, stress, food allergens (in young children)
• Microbiome: S. aureus colonisation in >90% of eczema skin (compared to 5% normal skin)

Pathophysiology

• Impaired epidermal barrier (filaggrin deficiency) leads to increased transepidermal water loss and allergen/irritant penetration
• Th2 immune activation produces IL-4, IL-13, IL-31 (pruritus mediator) driving inflammation
• Chronic scratching causes further barrier disruption (itch-scratch cycle)
• S. aureus colonisation releases superantigens that amplify inflammation

Typical Distribution by Age

• Infants (<2 years): face (cheeks), scalp, extensor surfaces
• Children (2-12 years): flexural surfaces (antecubital/popliteal fossae), wrists, ankles, neck
• Adults: flexures, hands, face, generalised; may be predominantly hand eczema

Clinical Features

• Intense pruritus (hallmark symptom)
• Dry, erythematous skin
• Acute: weeping, vesicles, crusting
• Chronic: lichenification (thickened, leathery skin), excoriations
• Xerosis (generalised dry skin)

Red Flags

• Eczema herpeticum: clustered vesicles/pustules, punched-out erosions, fever, systemic unwellness — dermatological emergency
• Widespread secondary bacterial infection: weeping, crusting, fever, cellulitis
• Erythroderma: >90% body surface area involved — risk of hypothermia, fluid loss
• Growth faltering in children with severe eczema and dietary restrictions
• Failure to respond to treatment — reconsider diagnosis (contact dermatitis, psoriasis, scabies, fungal infection)

Bedside

• Clinical diagnosis in typical cases — no investigations required
• Assess severity using validated tool (e.g. POEM — Patient-Oriented Eczema Measure)
• Body surface area assessment

Bloods

• Not routinely required
• Total IgE and specific IgE/skin prick testing: if food allergy suspected (particularly in children <2 with moderate-severe eczema; NICE CG116)
• FBC: eosinophilia may be present but not diagnostic

Microbiology

• Skin swab: if secondary bacterial infection suspected (S. aureus most common)
• Viral swab: if eczema herpeticum suspected (HSV PCR)

Special Tests

• Patch testing: if allergic contact dermatitis suspected (refer to dermatology)
• Skin biopsy: rarely needed; consider if diagnosis uncertain

Non-pharmacological

• Emollients: cornerstone of management; apply liberally and frequently (3-4× daily minimum)
  • Adults: 250-500g/week; children: 250g/week
  • Use as soap substitute (emulsifying ointment, Dermol 500)
  • Ointments (e.g. Epaderm, 50:50 liquid paraffin/white soft paraffin) are more effective than creams for dry skin
• Avoid triggers: biological washing powder, soaps/bubble bath, wool clothing
• Keep nails short (reduce excoriation)
• Lukewarm (not hot) baths
• Cotton clothing preferable

Pharmacological

Topical corticosteroids (NICE NG203):

• Mild: hydrocortisone 1% (face and flexures in children)
• Moderate: clobetasone butyrate 0.05% (Eumovate) — body, limbs
• Potent: betamethasone valerate 0.1% (Betnovate), mometasone furoate 0.1% — moderate-severe flares; short courses on body/limbs
• Very potent: clobetasol propionate 0.05% (Dermovate) — specialist-initiated for severe refractory areas
• Apply once daily during flare, for 7-14 days then step down
• Use fingertip units for dosing guidance
• Proactive maintenance: potent TCS twice weekly to relapse-prone areas (steroid-sparing strategy)

Topical calcineurin inhibitors:

• Tacrolimus 0.03% (children) or 0.1% (adults): for moderate-severe eczema, particularly face/flexures
• Pimecrolimus 1%: for mild-moderate eczema
• Steroid-sparing; no skin atrophy risk

For infected eczema:

• Flucloxacillin 500mg QDS for 7 days (or clarithromycin if penicillin-allergic)
• Antiseptic bath additives (limited evidence)

For eczema herpeticum:

• Oral aciclovir 400mg 5× daily for 5 days (or IV if severe)
• Urgent same-day dermatology assessment

Severe/refractory eczema (specialist-initiated):

• Phototherapy (narrowband UVB)
• Systemic immunosuppressants: methotrexate, azathioprine, ciclosporin, mycophenolate
• Dupilumab (anti-IL-4/IL-13 monoclonal antibody): NICE TA534 for moderate-severe atopic eczema in adults after ≥1 systemic treatment
• JAK inhibitors (baricitinib, upadacitinib, abrocitinib): emerging treatments for moderate-severe eczema

Referral Criteria

• Eczema herpeticum: urgent/same-day dermatology
• Severe eczema not responding to optimal topical treatment: dermatology referral
• Diagnostic uncertainty
• Suspected allergic contact dermatitis: patch testing referral
• Consideration for systemic therapy or phototherapy

• 60-70% of childhood eczema clears by adolescence
• 10-15% continue to have eczema into adulthood
• Adult-onset eczema tends to be more persistent
• Eczema herpeticum: excellent prognosis with prompt aciclovir treatment; risk of severe complications if delayed
• Atopic march: 30% of children with eczema develop asthma; 35% develop allergic rhinitis
• Quality of life impact is significant: comparable to diabetes and heart disease on QoL measures
• Secondary infection: occurs in >50% of moderate-severe eczema patients at some point

Fingertip Unit (FTU) Guide

Topical Corticosteroid Potency Ladder