Eczema

Question 1

What is atopic eczema?

Answer 1

Atopic dermatitis
Inflammatory skin condition and commonly affects flexural areas
Multiple types and spectrum of severity
Wide range of external and internal factors

Question 2

Describe the pathophysiology of atopic eczema

Answer 2

Disrupted skin barrier
Antigens get in - dermal dendritic antigen presenting cells
T cell activated response - Th2 predominates drive
Itch and scratch cycle

Question 3

What 2 things are the main aspects of eczema?

Answer 3

Barrier dysfunction and inflammation

Question 4

What is the aetiology of eczema?

Answer 4

Genetics, immunology and environment

Question 5

What is the definition of atopic eczema?

Answer 5

An itchy skin condition in the last 12 months
Plus 3 of following - onset before age 2, history of flexural involvement, dry skin and other atopic disease - asthma, hay fever or allergy

Question 6

Describe the pathogenesis of eczema

Answer 6

Genetics - key role of Filaggrin gene and atopic family history
Epidermal barrier dysfunction
Environmental factors
Immune system dysregulation

Question 7

Describe the pathology of atopic eczema

Answer 7

Spongiosis (intercellular oedema) within epidermis
Acanthosis (thickening of the epidermis)
Inflammation - superficial perivascular lymphohistiocyctic infiltrate

Question 8

What are the clinical features of atopic eczema?

Answer 8

Itch
Distribution - flexures, neck, eyelids, face, hands and feet
Acute changes - pruritus, erythema, scale, papules and vesicles
Chronic changes - lichenification, plaques and fissuring

Question 9

What is Danny Morgan line?

Answer 9

Increased eye fold in atopic eczema

Question 10

What are some other types of exogenous eczema?

Answer 10

Contact dermatitis - irritant or allergic
Lichen simplex
Photoallergic or photo-aggravated eczema

Question 11

What are some other types of endogenous eczema?

Answer 11

Endogenous - atopic, discoid, venous, seborrheic dermatitis, pompholyx and juvenile plantar dermatitis
Asteatosic

Question 12

What is allergic contact dermatitis?

Answer 12

Type 4 hypersensitivity
Delayed hypersensitivity - can take 48-72hrs to develop

Question 13

Describe the process of allergic contact dermatitis

Answer 13

Antigen presenting cells take hapten/ allergen to LN ad present to naive T cells
Clonal expansion of these T cells, released into bloodstream
When these T cells next encounter hapten - mast cell degranulation, vasodilatation and neutrophils

Question 14

What is irritant contact dermatitis?

Answer 14

Skin injured by friction (micro-trauma or cumulative) or environmental factors (cold, over exposure to water and chemicals like acids, alkalis, detergents and solvents)

Question 15

What occupation can be affected by irritant contact dermatitis?

Answer 15

Hairdressers, NHS staff, cleaners, nappy rash and dermatitis from soap accumulation under ring

Question 16

How is allergic contact dermatitis diagnosed?

Answer 16

Potential allergens applied by Fin chambers
Baseline/ standard series - applied to all patients
Applied Mon, remove Wed and re-assess Fri

Question 17

Describe seborrheic dermatitis - infants

Answer 17

Distinctive pattern
Predilection for scalp and proximal flexures - likes hair bearing sites
Under 6 months age usually
Often clears within weeks of treatment

Question 18

Describe seborrheic eczema - adults

Answer 18

Chronic dermatitis
Malassezia yeast is increased in scaly epidermis of dandruff and seborrheic dermatitis
Red scaly marginalised lesions covered in greasy looking scales
Distinctive distribution - areas rich in sebaceous glands (scalp, face and upper trunk)

Question 19

What could be a precursor for seborrheic eczema?

Answer 19

Dandruff
May gradually progress through redness, irritation and increased scaling

Question 20

What is the treatment of seborrheic eczema?

Answer 20

Topical anti-yeast - ketoconazole
If severe then consider HIV test

Question 21

What is discoid eczema?

Answer 21

Circular patches of eczema
Often the cause is unknown
May develop at sites of trauma/ irritation

Question 22

Describe pompholyx/ vesicular eczema

Answer 22

Palms and soles
Intensely itchy
More common under 40
Sudden onset of crops of vesicles
Resolution can include desquamation

Question 23

Describe asteatotic eczema

Answer 23

Very dry skin and cracked scaly appearance
Most commonly skins affected
Climate - heat
Excessive washing/ soaps

Question 24

Describe venous eczema

Answer 24

Stasis eczema or varicose eczema
Increased venous pressure
Oedema
Ankle and lower leg involved
Resolution of oedema can help - compression stockings

Question 25

Describe eczema herpeticum

Answer 25

Disseminated viral infection
Fever and often unwell
Itchy clusters of blisters and erosions - punched out
HSV 1 and 2
Swollen lymph glands

Question 26

What is the treatment for eczema herpeticum?

Answer 26

Admission, antivirals, and consider secondary bacterial infection
Watch in small children for systemic infection developing

Question 27

What is the treatment of eczema?

Answer 27

Avoid causation/ exacerbating factors
Emollients - ointments, cream and lotions
Soap substitutes
Intermittent topical steroids
Sometimes need antihistamines or antimicrobials
Calcineurin inhibitors

Question 28

What are some calcineurin inhibitors?

Answer 28

Topical Pimecrolimus and Tacrolimus

Question 29

What is the treatment of severe eczema?

Answer 29

Ultraviolet light
Immunosuppression - azathioprine, ciclosporin, mycophenolate mofetil and methotrexate
Biologic - Dupilumab

Question 30

What can steroids induce?

Answer 30

Striae