Atopic dermatitis and eczema

Question 1

What is atopic dermatitis and eczema?

Answer 1

Inflammatory skin condition characterised by dry, pruritic skin with a chronic relapsing course

Question 2

Describe the epidemiology behind atopic dermatitis and eczema?

Answer 2

M=F, usually presents in childhood

Question 3

What can cause atopic dermatitis and eczema?

Answer 3

Genetics (polygenic inheritance - predisposition for increased IgE formation and sensitisation = type 1 hypersensitivity), triggers (dust mites, heat, humid climate, stress, skin irritation)

eczema:
A genetic defect causing a loss of function of the protein filaggrin is thought to be an underlying cause of Atopic Eczema. Filaggrin (filament aggregating protein) has an important role in maintaining the skin barrier. An impaired skin barrier is thought to enable easier entry of allergens. However, the cause of Atopic Eczema is not fully understood and exacerbating factors such as infection, sweat, heat and stress also contribute

Question 3

What are the risk factors for atopic dermatitis and eczema?

Answer 3

allergic rhinitis (hayfever), age <5 years, family history of eczema, PMH/FH of atopy (food allergies, asthma)

Question 3

What is meant by “contact dermatitis”?

Answer 3

Type of eczema occuring following exposure to a causative agent (hx may say patient has new occupation).

Question 3

What are the presenting symptoms and signs of atopic dermatitis and eczema?

Answer 3

1. Pruritus → may have excorations (scratch marks)
2. Dry Skin
3. Sites of Skin Involvement → infants typically show involvement of the cheeks, forehead, scalp and extensor surfaces. Children typically have involvement of the flexures, particularly the wrists, ankles, and antecubital and popliteal fossa.
4. Acute Flares → erythema, scaling, vesicles, papules
5. Lichenification (thick leathery skin due to constant scratching) and Hyperpigmentation → if chronic
6. Eczema Herpeticum (Medical Emergency) ⇒ severe infection of the skin by HSV 1 or 2. Commonly seen in children with atopic eczema and presents as a rapidly progressing painful rash. Punched out erosions are typically seen. Potentially life-threatining, hence children should be admitted for IV aciclovir.
   - Diagnosis can be confirmed with a swab & Tzanck test.

Question 4

What investigations are used to diagnose/ monitor atopic dermatitis and eczema?

Answer 4

1. Clinical Diagnosis
2. Elevated IgE Levels
3. Contact Dermatitis ⇒ skin patch testing (for type IV hypersensitivity)
   - (Skin Prick Testing = type I hypersenitivity such as food allergies or urticaria)

Question 5

How is atopic dermatitis/ eczema managed?

Answer 5

1. Avoid allergens/ triggers
2. Keep the area cool and dry.
3. Emollients → improve skin barrier function by rehydrating the skin, applying an emollient while the skin is already moist (following a bath or shower) helps keep the moisture in.
4. Topical Corticosteroids → hydrocortisone (specific guidance on severity- check last flash card)
5. Severe Cases ⇒ systemic immunosuppressive agents (Oral Ciclosporin)
6. Psychological support may be needed.

Question 6

What complications may arise following atopic dermatitis/ eczema?

Answer 6

1. Complications → psychological stress, adverse effects of drugs
2. Prognosis → chronic disease with a varying course. Approximately 60% of children will have symptom resolution as they enter puberty, but relapse may occur in 50%

Question 7

What are the different categories for the severity of eczema?

Answer 7

1. Mild - areas of dry skin, and infrequent itching (with or without small areas of redness)
2. Moderate - areas of dry skin, frequent itching, and erythema (with or without excoriation and localized skin thickening)
3. Severe - widespread areas of dry skin, incessant itching, and erythema (with/without excoriation, extensive skin thickening, bleeding, oozing, cracking, and alteration of pigmentation)
4. Infected - if eczema is weeping, crusted, or there are pustules, with fever or malaise

Question 8

How does the management of eczema change with each severity?

Answer 8

1. Mild eczema - liberal emollient usage + mild topical corticosteroid (such as hydrocortisone 1%) for areas of red skin.
2. Moderate eczema - liberal emollient usage + moderate topical corticosteroid (such as clobetasone butyrate 0.5% - Eumovate) for 5 days. Hydrocortisone 1% should be used for the face and flexures.
3. Severe eczema - liberal emollient usage + potent topical corticosteroid (for example betamethasone valerate 0.1% - Betnovate) to be used on inflamed areas. For the face and flexures, use a moderate potency corticosteroid (such as Eumovate).

Question 9

When is a referral to dermatology required in the case of eczema?

Answer 9

Refer to Dermatology if:

• Eczema is severe and has not responded to optimum topical treatment after 1 week (urgent referral; within 2 weeks)
• The diagnosis is, or has become, uncertain.
• Current management has not controlled eczema satisfactorily (for example the person is having one to two flares per month), or the person is reacting adversely to many emollients.
• Facial eczema that is treatment-resistent.
• Contact allergic dermatitis is suspected