Eczema

Question 1

What is the diagnostic criteria for eczema?

Answer 1

Itchy skin condition in last 12 months plus 3 of:

• onset 2yo
• history of flexural involvement
• history of generally dry skin
• history of other atopic disease or history in 1st degree relative in <4yo

Question 2

What are the causes/risk factors of eczema?

Causes of acute flares?

Answer 2

Genetics

• many genes implicated
• key role for Filaggrin gene
• atopic FH

Epidermal barrier dysfunction
Environmental factors

Acute flares

• viral illness or period of poor health
• stress
• environmental triggers - heat, cold, allergens
• food allergies

Question 3

What are the symptoms/signs of eczema?

Answer 3

Itch, redness, scaling, papules, vesicles
Flexural but can involve all body sites
Chronic changes
Lichenification, plaques, fissuring

Question 4

How is eczema investigated?

Answer 4

Patch testing

• applied monday
• remove wednesday
• re-assess friday

Most reactions at 96 hours

Question 5

What are the different types of eczema?

Answer 5

Exogenous

• contact dermatitis (irritant, allergic)
• lichen simplex
• photoallergic, photoaggravated

Endogenous

• atopic
• discoid
• venous
• seborrheic dermatitis
• pompholyx
• juvenile plantar dermatitis
• asteatotic

Question 6

What are the general different types of eczema treated?

Answer 6

Patient education
Avoid causative/exacerbating factors
Emollients
Soap substitutes
Intermittent topical steroids
Antihistamines/antimicrobials
Calcineurin inhibitors
UV
Immunosuppression

Question 7

What are different types of emollients?

Answer 7

Ointments - greasy but effective
Creams - lighter
Lotions - more watery

Question 8

What different steroids are used?

Answer 8

Hydrocortisone (lower potency)

Betamethasone (higher potency)

Question 9

What are the calcineurin inhibitors?

Answer 9

Topical pimecrolimus and tacrolimus

Question 10

What different immunosuppressants are used?

Answer 10

Azathioprine
Ciclosporin
Mycophenolate mofetil
Methotrexate

Question 11

When might you use anti-fungals in eczema and which anti-fungal?

Answer 11

Seborrheic keratoses - ketoconazole

- consider HIV test if severe

Question 12

What is the pathology of eczema?

Answer 12

Spongiosis - intercellular oedema within the epiudermis
Acanthosis - thickening of epidermis
Inflammation - superficial perivascular lymphohistiocytic infiltrate

Question 13

What are the histological features of acute dermatitis?

Answer 13

Acute dermatitis

• intercellular oedema within the epidermis
• can lead to accumulation of intra-epidermal vesicles
• infiltration of the epidermis with lymphocytes is common
• dermal changes include varying degrees of oedema and a superficial perivascular infiltrate with lymphocytes, histiocytes and occasional neutrophils and oesinophils

Question 14

What are the histological features of chronic dermatitis?

Answer 14

In chronic spongiosis dermatitis, the degree of spongiosis is often mild and difficult to appreciate
Vesiculation is uncommon
There is significant epidermal acanthosis, which may show a psoriasiform pattern with hyperkeratosis, hypergranulosis and minimal parakeratosis
Fibrosis of the papillary dermis may be present