Atopic dermatitis and eczema

Overview

•Cardinal symptom: pruritus - often severe, worse at night, disrupts sleep

•Flexural involvement - antecubital and popliteal fossae in children; face and neck in infants

•Xerosis - dry skin present even between flares

•Lichenification - skin thickening from chronic scratching; long-standing disease

•Weeping/crusting - suggests active inflammation or secondary bacterial infection

Management

•Foundation (all severities): emollients liberally and frequently; use as soap substitute - single most important treatment

•First-line (mild): hydrocortisone 1% - for mild eczema or sensitive areas (face, neck, flexures)

•Second-line (moderate): betamethasone valerate 0.025% or clobetasone butyrate 0.05%

•Second-line (severe/sensitive areas): topical calcineurin inhibitors - tacrolimus 0.1% (adults) or 0.03% (children ≥2 years); pimecrolimus 1% cream - especially useful on face/neck where steroids risk atrophy

🥉 Third-line

•wet wrap therapy (children, severe flares); systemic - oral ciclosporin, methotrexate, or biologic dupilumab (≥6 years) - specialist input required

•Antihistamines: do NOT routinely prescribe for itch; 7-14 day trial of sedating chlorphenamine acceptable in children ≥6 months if sleep significantly disrupted

Complications

🚨

Eczema herpeticum is a dermatological emergency. Widespread punched-out erosions and clustered vesicles + fever + malaise + lymphadenopathy in a patient with eczema = urgent hospital admission for systemic aciclovir. Most dangerous in children under 2 years. Do NOT treat with topical steroids, flucloxacillin, or reassure.

•Secondary bacterial infection - Staphylococcus aureus most common; impetigo-like crusting and weeping

•Topical steroid side effects - skin atrophy, telangiectasia, striae, adrenal suppression (potent steroids); key driver for using calcineurin inhibitors on sensitive areas

•Atopic march - eczema in infancy increases risk of subsequent food allergy, allergic rhinitis, and asthma

Subtypes to recognise

Key eczema subtypes

Subtype	Site	Key feature
Pompholyx eczema	Palms, fingers (and soles)	Deep-seated vesicles; triggered by heat/sweating/humid environments; followed by scaling and fissuring
Discoid eczema	Limbs (especially legs)	Coin-shaped plaques
Stasis (varicose) dermatitis	Lower legs	Associated with chronic venous insufficiency
Atopic eruption of pregnancy	Face, neck, chest, extensor surfaces	Most common dermatosis in pregnancy (~1 in 300); itchy erythematous papules and excoriated nodules; 2nd/3rd trimester; benign - no adverse fetal effects

🎯

Distinguish atopic eruption of pregnancy (excoriated papules/nodules, benign) from pemphigoid gestationis (blistering, periumbilical, serious) and intrahepatic cholestasis (pruritus without primary rash, bile acid elevation).

Infected eczema

•If not systemically unwell - do not routinely prescribe antibiotics; optimise topical treatment

•If antibiotics indicated - topical fusidic acid 2% (5-7 days) or oral flucloxacillin first choice

•Penicillin allergy - clarithromycin (erythromycin in pregnancy)

•If systemically unwell (fever, rapidly spreading) - oral/IV antibiotics and consider admission