Eczema

Question 1

Describe acute eczema

Answer 1

Rash with inflamed red skin that is poorly demarcated and less scaly than psoriasis

Barrier function of the epidermis is abnormal and skin is easily irritated

Itchy and often associated excorations

Question 2

What are types of eczema?

Answer 2

Endogenous
Atopic, seborrhoeic, varicose from venous stasis, discoid

Exogenous
Allergic contact or irritant contact

Question 3

What are causes of atopic eczema?

Answer 3

Multifactorial
GeneticInfection
Allergens - avoidance of allergens is difficult and of limited beenfit
Food allergy is rarely the cause
Consider if there is a clear trigger

Question 4

How is eczema diagnosed?

Answer 4

Child must have itchy skin ± 3 or more of:
Onset before 2 yrs
Past flexural involvement
Hx of generally dry skin
Personal history of other atopy or Hx or atopy in 1st degree relative if <4y
Visible flexural dermatitis (or on cheeks, forehead, outer side of limbs)
Lichenification from chronic rubbing

Atopic eczema spares the nappy area

Question 5

What are features of eczema?

Answer 5

Typically presents before 6m but clears by 5 -10 years

Face and trunk affected in infants
Younger children - eczema on extensor srufaces
Older children - flexor surfaces affected and creases of the face and neck

Question 6

What is management of eczema?

Answer 6

Explain: control not cure, multifactorial cause causing breakdown of skin barrier, fluctuates, report any sever weeping rash around the mouth

Emollients
Large quantities applied liberally
Treat dryness and act as barrier
If a topical steroid is also being sued, emollient should be applied first followed by waiting 30m before applying the steroid

Topical steroids
Use for exacerbations and only on active eczematous skin
Apply once each day 30m after emollient
Explain safe if used as prescribed

UV radiation
Immunosuppressants

Question 7

What are prognostic markers of severe disease?

Answer 7

Onset at 3-6m age
Severe disease in childhood
Associated asthma or hay fever
Small family size
High IgE serum levels

Question 8

What is Mx for itch?

Answer 8

Sedating antihitamines
.e.g Hydroxyzine
Used intermittently at night can reduce the itch/scratch cycle
Keep fingernails short
Advise pressing the skin rather than scratching or rubbing

Question 9

What is adult seborrhoea dermatitis? What is it known as in babies?

Answer 9

Seborrhoeic dermatitis in adults is a chronic dermatitis thought to be caused by an inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia furfur

Eczematous lesions on the sebum-rich areas:
scalp (may cause dandruff), periorbital, auricular and nasolabial folds

otitis externa and blepharitis may develop

Can be severe if HIV +

Cradle cap in babies

Question 10

What is management of adult seborrhoeic dermatitis

Answer 10

Scalp disease management
Zinc pyrithione (‘Head & Shoulders’) and tar (‘Neutrogena T/Gel’) are first-line
Second-line agent is ketoconazole

Face and body management
topical antifungals: e.g. ketoconazole
topical steroids: best used for short periods
difficult to treat - recurrences are common

Question 11

What is irritant contact dermatitis? Management?

Answer 11

Non-allergic reaction due to weak acids or alkalis
Erythema is typical, weeping precedes dry fissuring

Detergents, soaps, oils, solvents, water if repeated

Avoid all irritants
Hand care
Regular emollients
Careful drying
Topical steroids as needed for acute flare-ups

Question 12

What is allergic contact dermatitis? Management?

Answer 12

Type IV hypersensitivity reaction
Presents as an acute weeping eczema which predominately affects the margins of the hairline
Often seen on head following hair dyes
There is sharp cut-off where contact ends

Allergens:
Nickel (jewellery, watches, coins) 
Chromates (cements, leather)
Creams
Cosmetics
Rubber
Plants
Pattern of contact gives clue

MX
Consider patch testing
Avoidance of implicated allergens
Use topical steroid appropriate for severity

Question 13

What are side effects of topical corticosteroids?

Answer 13

Skin thinning
Irreversible striae
Telangiectasia
Worsening of untreated infection
Contact dermatitis

Adrenal suppression (rare)

Question 14

How can amount of topical corticosteroid require be estimated?

Answer 14

1 fingertip unit FTU = 0.5g sufficient to treat a skin are of about twice the flat of adult hand

so 1 FTU = 2 adult hands

so face and neck = 2.5 FTU

Hand and fingers - front an back = 1 FTU

Foot all over = 2 FTU

Question 15

What are different potency of topical steroids?

Answer 15

Mild - hydrocoritsone
Moderate - clobetasone - eumovate
Potent - betamethoasone (Betnovate RD)
Potent - mometasone - elocon
Very potent - dermovate - clobetasol

Question 16

What investigations in allergic contact dermatitis?

Answer 16

Patch testing is the investigation of choice for suspected allergic contact dermatitis. Various allergens are applied to the patient’s back, and the skin assessed at 48 hours and 7 days for any reaction. Standard batteries of allergens are used, in addition to samples of any substances the patient suspects.

Question 17

What advice for applying emollients?

Answer 17

Initially applying emollients 2-3 times per day (including immediately after washing)
When skin worsens emollients can be applied hourly
Wash hands before applying emollient to prevent infection of damaged skin
Either dispense emollient using a pump or spoon from a tub to avoid contamination of the tub.
Apply emollient generously to all areas of the body onto the skin in a downward motion in direction of hair
Do not rub in emollients, but rather leave them to soak in.