Dermatology
Eczema / Atopic Dermatitis
Library·Dermatology·Eczema
Don't miss
- Eczema herpeticum - monomorphic vesicles or punched-out erosions, unwell child - aciclovir, dermatology
- Bacterial superinfection - weeping, golden crust, cellulitis
- Failure to thrive with eczema - immunodeficiency syndrome (rare but consider)
- Erythroderma (>90% BSA) - admission for fluid, temperature
First-line
- Step 1
- Emollients always - moderate eczema in a child needs ~250 g/week
- Step 2-3
- TCS by site potency: mild face/groin, moderate body, potent palms/soles short course
- Step 4
- Topical calcineurin inhibitors for face and flexures
- Step 5
- Dupilumab referral - PHARMAC-funded for moderate-severe with inadequate topical response
Refer when
- Moderate-severe disease failing optimised topical therapy
- Eczema herpeticum or recurrent serious infection
- Diagnostic uncertainty - patch testing for contact
- Significant impact on growth, sleep, school, or mental health
Tell whanau
- Steroid phobia is common - the under-treatment risks are bigger than thinning
- Use enough emollient that the skin feels greasy 30 minutes later
- Treat to clear, then maintain twice-weekly to prevent flares
- Triggers vary - common ones are heat, soap, stress, infection
Atopic dermatitis affects around 15-20% of children and 2-5% of adults in New Zealand.1 It is part of the atopic triad alongside asthma and allergic rhinitis, and family history is strongly predictive. The skin barrier dysfunction model - rather than a purely immunological one - has reshaped how we think about prevention and early treatment.
❍ Diagnosis
Clinical diagnosis. Chronic or relapsing pruritic dermatitis with typical distribution (flexural in older children and adults; facial and extensor in infants) plus at least three of: personal or family history of atopy, dry skin, onset before age 2, visible flexural involvement.2
The distribution shifts with age: infants present with facial, scalp, and extensor surface involvement; from toddlerhood the classic flexural pattern (antecubital and popliteal fossae, wrists, ankles) predominates. In adults, the pattern is more variable and hand eczema is common. Seborrhoeic dermatitis, psoriasis, and contact dermatitis are the main differentials in adults.
❍ Stepwise management
Step 1 - Emollients, always. Applied at least twice daily to all affected and unaffected skin. This is the foundation of eczema management, not an adjunct. Quantities matter - a child with moderate eczema may need 250 g per week. Prescribe by weight, not tube size. Greaser preparations (ointments, thick creams) are more effective than lotions; the greasier the better for dry skin, though patient preference and season affect adherence.
Step 2 - Mild topical corticosteroid for flares. 1% hydrocortisone for face and flexures. Moderate potency (betamethasone valerate 0.02%) for body flares. Use the finger-tip unit (FTU) guide for dosing - one FTU covers approximately two adult palms.
Step 3 - Moderate or potent TCS short courses. For persistent or severe flares, with clear instructions on duration and tapering. Document the potency and site - strong TCS (e.g. betamethasone valerate 0