Eczema

Question 1

What is eczema?

Answer 1

A chronic relapsing skin condition characterised by an itchy red rash that favours skin creases / flexors i.e. folds of the elbows or behind the knees.

Question 2

How common is eczema?

Answer 2

Affects 15-20% of school children and 2-10% of adults.

Question 3

Who does it affect?

Answer 3

80% present before the age of 5

Typically, presents before 6 months but clears in ~50% by age 5 and 75% by age 10.

Question 4

What causes eczema?

Answer 4

Not fully understood but forms part of atopic triad: eczema, asthma, allergic rhinitis.

A primary genetic defect in skin barrier function appears to underlie atopic eczema.

It is exacerbated by:
=> Environmental irritants and allergens

=> Extremes of temperature
=> Humidity/sweating

=> Food allergy

=> Skin infections

=> Stress

=> Hormonal changes in women

Question 5

What are the risk factors for eczema?

Answer 5

1. Family hx of atopy

2. Personal hx of atopy

Question 6

How does eczema present?

Answer 6

1. Pruritus (if it doesn’t itch, very unlikely to be eczema)
2. Ill-defined erythematous dry scaly patches
3. In infants: face and trunk affected

In young children: extensor surfaces affected

In older children: flexural surfaces affected + creases of face & neck (typical presentation)

4. Excoriations
5. Lichenification
6. Nail pitting/ridging of nails

Question 7

What are the differentials for eczema?

Answer 7

1. Psoriasis
2. Contant dermatitis
3. Seborrheic dermatitis
4. Fungal infection
5. Scabies

Question 8

Eczema is a clinical diagnosis - investigation not needed.

Answer 8

INFO CARD

Question 9

How is eczema treated?

Answer 9

1. Avoid exacerbating factors / irritants
2. Frequent emollients
3. Bath oil/soap substitute
4. Topical steroids for flare up
   * emollient should be applied first and wait 30 mins before applying steroid
5. Topical immunomodulators used as steroid sparing agents e.g. tacrolimus, pimecrolimus
6. Oral sedating anti-histamines
7. Antibiotics for secondary bacterial infections
8. Phototherapy and immunosuppressants for severe, non-responsive case

Question 10

What is the prognosis of asthma?

Answer 10

Relapsing course with tendency to improve in adulthood

Question 11

What are the complications of eczema?

Answer 11

Secondary bacterial infections - crust weepy lesions

Secondary viral infections - molluscum contagiosum, viral warts, eczema herpeticum

Question 12

What is eczema herpeticum?

How does it present?

How is it treated?

Answer 12

Severe primary skin infection by herpes simplex virus 1 or 2

Commonly seen in children with atopic eczema and presents as a rapidly progressing painful rash.

=> monomorphic punched out erosions (circular, depressed ulcerated lesions) usually 1-3mm in diameter

Treatment: admit in hospital + IV aciclovir

*Life-threatening condition!!

Question 13

Always use weakest steroid cream which controls eczema symptoms:

MILD:
=> Hydrocortisone 0.5-2.5%

MODERATE:
=> Betamethasone valerate 0.025% (Betnovate)

=> Clobetasone butyrate 0.05% (Eumovate)

Answer 13

POTENT:
=> Fluticasone propionate 0.05% (Cutivate)

=> Betamethasone valerate 0.1% (Betnovate)

VERY POTENT:
=> Clobetasol propionate 0.05% (Dermovate)

*1 finger tip unit = 0.5g - sufficient to treat a skin are 2x the palm of hand