Atopic Dermatitis (Eczema)
Atopic dermatitis, also known as eczema, is a chronic inflammatory skin condition characterised by dry, itchy skin and an episodic course of flares and remission.
This updated UKMLA guide to atopic dermatitis is based on NICE CG57 and NICE CKS, which covers causes, risk factors, symptoms, complication, diagnosis, and management.
Epidemiology
Atopic dermatitis can present at any age, but most frequently presents in childhood
- >70% cases occur before 5 y/o
- ~30% cases first present in adulthood
Causes and Risk Factors
There is no single known cause of atopic eczema. It is a multifactorial condition involving genetic susceptibility, immune dysregulation, and environmental triggers. These factors contribute to a dysfunctional skin barrier, making the skin more prone to dryness, irritation, inflammation, and infection.
There is a strong genetic susceptibility
- ~70% patients have a family history of atopy (e.g. atopic dermatitis, asthma, hay fever)
- ~80% of children develop atopic dermatitis when both parents are affected; ~60% if one parent is affected
- Filaggrin gene mutations are one of the most established genes involved in atopic dermatitis (thought to contribute to ~50% cases)
Clinical Features
| Course and progression | Atopic dermatitis typically follows an episodic course, with periods of flare-ups and remission. |
| Triggers | Very common / broadly recognised triggers:
More individual-specific triggers:
|
| Rash distribution | The location and distribution of atopic dermatitis vary with age:
|
| Signs and symptoms | The hallmark symptom is itching (the diagnosis is unlikely if there is no itch)
Acute flares may vary in appearance:
Secondary bacterial infection should be considered if there is weeping / honey-colour crusting / pustules / new pain + fever or malaise Chronic eczema appearance:
|
See the investigation and diagnosis section below for diagnostic criteria.
Complications
Infections are key acute complications of atopic dermatitis:
- Staphylococcus aureus infection may present as impetigo or as an acute flare
- HSV infection may present as grouped vesicles and punched-out erosions
- Superficial fungal infections are more common
The most serious complication is eczema herpeticum – a potentially life-threatening disseminated HSV infection of eczematous skin (classically seen in patients with atopic dermatitis).
Features include:
- Rapidly worsening, painful rash
- Clusters of monomorphic vesicles and punched-out erosions
- Haemorrhagic crusting
- Widespread lesions that may coalesce into large, denuded or bleeding areas
- Systemic toxicity e.g. fever, lymphadenopathy, and malaise
Atopic dermatitis also causes long-term psychosocial problems:
- Sleep disturbance due to itching is a major implication, which can impair concentration, mood, and daytime functioning
- Depression, anxiety
- Reduced self-esteem and poor body image, which may affect social development and quality of life
- Mainly seen in young children
- Impact on school (e.g. time away from school, impaired performance, social restrictions, teasing, bullying)
- Higher rates of behavioural problems, fearfulness, and dependency on parents
Investigation and Diagnosis
Atopic dermatitis is a clinical diagnosis
- Investigations are NOT necessary for establishing a diagnosis
- It is important to identify any triggers via a comprehensive history (NICE CKS explicitly noted to advise avoidance of over-the-counter tests, as these are of no proven value and most people do NOT need allergy testing)
Diagnostic Criteria
NICE outlined the following clinical diagnostic criteria:
- Itchy skin, AND
- At least 3 of the following:
- Onset <2 y/o (this criterion should not be used in <4 y/o)
- Visible flexural eczema involving the skin creases (or in ≤18 months: visible eczema on the cheeks and/or extensor areas)
- Personal history of flexural eczema (or in ≤18 months: history of eczema on the cheeks and/or extensor areas)
- Personal history of dry skin in the last 12 months.
- Personal history of asthma or allergic rhinitis (or in <4 y/o: this criterion counts if there is family history of atopic disease in a first-degree relative)
NICE notes that these criteria apply to all ages, social classes, and ethnic groups. However, in children of Asian, black Caribbean, and black African ethnic groups, atopic eczema can affect the extensor surfaces rather than the flexures, and discoid (circular) or follicular (around the hair follicles) patterns may be more common.
Management
Conservative / General Management
For all patients, includes:
- Trigger avoidance
- Manage itch and scratching
- Educate on flare recognition
Severity Category
| Category | Appearance | Psychological impact |
|---|---|---|
| Mild |
|
Little impact on everyday activities, sleep and psychosocial well-being
Sleep is unaffected |
| Moderate |
|
Moderate impact on everyday activities, sleep and psychosocial well-being
Frequently disturbed sleep |
| Severe | Widespread areas of dry skin with:
|
Severe limitations of everyday activities and psychosocial functioning
Loss of sleep every night |
| Infected |
|
n/a |
Pharmacological Management
The mainstay of atopic dermatitis management is frequent and liberal use of topical emollients. Emollients should be used in much larger quantities than other topical treatments (e.g. topical corticosteroids), typically by at least 10 times as much.
Brief overview:
| Severity | Management options |
|---|---|
| Mild |
|
| Moderate |
|
| Severe |
|
Mild Eczema
| Flare management | Consider a mild topical corticosteroid (e.g. hydrocortisone 1%) – to be continued for 48 hours after the flare is controlled
Continue regular emollient use – apply the steroid first, and wait for 15-30 min before applying the emollient |
| Maintenance therapy | Advice on regular emollient use
|
Active follow-up is rarely required for mild eczema, unless the person or carer requests it
Moderate Eczema
| Flare management | Moderately potent topical corticosteroid (e.g. betamethasone valerate 0.025% or clobetasone butyrate 0.05%) – to be continued for 48 hours after the flare is controlled
For delicate areas of skin (face and flexures):
Other topical therapies:
If there is severe itch / urticaria:
|
| Maintenance therapy | Advice on regular emollient use
Consider preventive/maintenance treatment
Consider localised medicated dressings / dry bandages with emollients to treat areas of chronic lichenified skin |
Severe Eczema
| Flare management | Potent topical corticosteroid (e.g. betamethasone valerate 0.1%) – to be continued for 48 hours after the flare is controlled
For delicate areas of skin (face and flexures):
Other topical therapies:
If there is severe itch / urticaria:
|
| Maintenance therapy | Advice on regular emollient use
Consider preventive/maintenance treatment
Consider localised medicated dressings / dry bandages with emollients to treat areas of chronic lichenified skin Further secondary care options:
|
Do NOT use potent corticosteroids in children under 12 months old, or very potent corticosteroids in children of any age, without specialist dermatological advice.
Infected Eczema
Admission to hospital is indicated if eczema herpeticum is suspected
- Immediate treatment with IV aciclovir is necessary
DO NOT routinely offer topical / oral antibiotic for secondary bacterial infection of eczema, unless systemically unwell:
- If antibiotic is offered, 1st line: flucloxacillin (alternative: clarithromycin)
- For localised infection: consider topical fusidic acid
Episodes of infected eczema usually co-exist with a flare and will require concomitant treatment as described above.
Dry bandages and medicated dressings (including wet wrap therapy) should NOT be used to treat infected atopic eczema.
References