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Flashcards in Lecture 4 Eczema Deck (24)
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1

T cell responsible for acute stage of eczema

Th2

2

T cel responsible for chronic sage of eczema

Th1

3

Clinical features of Atopic eczema

• Itchy skin condition in the last 12 months

Plus 3 of the following:
• Onset before age 2
• History of flexural involvement
• History of generally dry skin
• History of other atopic disease
• History in 1st degree relative if under 4 yrs

4

Pathogenesis of Eczema

– Key role for Filaggrin gene
– Atopic family history

• Epidermal barrier dysfunction
• Environmental factors
• Immune system dysregulation

5

Pathology of eczema

• Spongiosis (intercellular oedema) within the epidermis.
• Acanthosis (thickening of the epidermis).
• Inflammation - Superficial perivascular lymphohistiocytic infiltrate

6

Histological features of acute dermatitis

Oedema in epidermis
superficial perivascular infiltrate with lymphocytes, histiocytes and occasional neutrophils and eosinophils.

7

Histological features of chronic dermatitis

• Chronic spongiotic dermatitis- degree of spongiosis is often mild and difficult to appreciate
• Significant acanthosis which may show a psoriasiform pattern with hyperkeratosis, hypergranulosis and miminal parakeratosis.
• Fibrosis of the papillary dermis may be present.

8

Clinical features of Atopic dermatitis/eczema

• Itch
• Distribution
– Flexures, Neck, Eyelids, Face, Hands and feet
– Tends to spare nappy area
• Acute changes
– Pruritus, Erythema, Scale, Papules, Vesicles
– Exudate, crusting, excoriation
• Chronic changes
– Lichenification, Plaques, Fissuring

9

External types eczema

• Contact dermatitis
– Irritant
– Allergic
• Lichen simplex
• Photoallergic or photoaggravated eczema

10

Internal types of eczema

– Atopic
– Discoid
– Venous
– Seborrhoeic dermatitis
– Pompholyx
– Juvenile plantar dermatitis
• Asteatotic

11

What type of sensitivity is allergic contact dermatitis

Type 4 Hypersensitivity
Delayed can take 48-72 hours

12

What are the causes of irritant contact dermatitis

1. Friction- micro-trauma, cumulative
2. Environmental factors
– Overexposure to water
– Chemicals such as acids, alkalis, detergents and solvents

13

What occupations increased for risk of developing irritant contact dermatitis

Hairdressers
NHS staff
Cleaners

14

Describe the process of patch testing

• Applied Monday (3 days)
• Remove Wednesday
• Re-assess Friday (2 days after removing)

15

What is Seborrhoeic dermatitis in infants

• Distinctive pattern
• Predilection for scalp, proximal flexures.
• <6months age usually.
• Often clears within weeks of treatment

16

What is Seborrhoeic Eczema- Adults

• Malassezia yeast increased in the scaly epidermis of dandruff and seborrehoic dermatitis.
• Red, sharply marginated lesions covered with greasy looking scales.
• Distinctive distribution – areas rich in supply of sebaceous glands (scalp, face, upper trunk

17

How do you treat Seborrhoeic Eczema- Adults

• Treat with topical anti-yeast (ketoconazole).

18

Describe discoid eczema

• Circular plaques of eczema.
• Cause often unknown.
• May develop at sites of trauma/irritation

19

Clinical features of Pompholyx/Vesicular Eczema

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

20

Clinical features of Asteatotic eczema

• Very dry skin.
• Cracked scaly appearance.
• Most commonly shins affected.
• Climate – heat
• Excessive washing/soaps

21

Clinical features of venous Eczema

• Increased venous pressure.
• Oedema.
• Ankle and lower leg involved.
• Resolution of oedema can help – compression stockings.

22

Topical steroids that can be used to treat eczema

• hydrocortisone (low)
• Betamethasone (potent)

23

Calcineuron Inhibitors that can be used to treat eczema

– Topical Pimecrolimus and Tacrolimus

24

Treatment for severe eczema

• Ultraviolet light.
• Immunosuppression.
– Azathioprine
– Ciclosporin
– Mycophenolate mofetil
– Methotrexate