Eczema

Question 1

Define

Answer 1

A pruritic papulovesicular skin reaction to endogenous or exogenous agents

→ Chronic, relapsing, inflammatory skin condition characterised by an itchy red rash

Question 2

Causes/ risk factors

Answer 2

There are lots of types because there are many different triggers

Exogenous

• Irritants (e.g. nappy rash)
• Contact (delayed type 4 hypersensitivity reaction to an allergen)
• Atopic

Endogenous

• Atopic
• Seborrhoeic
• Pompholyx (a type of eczema that affects the hands and feet)
• Varicose
• Lichen simplex

Varicose - due to increased venous pressure in lower limbs

Question 3

Epidemiology

Answer 3

Contact - prevalence: 4%

Atopic - onset in first year of life, childhood incidence: 10-20%

Question 4

Symptoms

Answer 4

Itching

Heat

Tenderness

Redness

Weeping

Crusting

Ask about occupational exposure to irritants 9eg.. Bleach)

Ask about personal/family history of atopy (e.g. asthma, hay fever)

Question 5

Sign

Answer 5

Acute

• Poorly demarcated erythematous oedematous dry scaling patches
• Papules
• Vesicles with exudation and crusting
• Excoriation marks

Chronic

• Thickened epidermis
• Skin lichenification
• Fissures
• Change in pigmentation

Based on type of eczema

• Atopic - mainly affects face and flexures
• Seborrhoeic - yellow greasy scales on erythematous plaques. Commonly found on eyebrows, scalp, presternal area
• Pompholyx - vesiculobullous eruption on palms and soles
• Varicose - associated with marked varicose veins
• Nummular - coin shaped, on legs and trunk
• Asteatotic - dry, crazy paring pattern

Question 6

Investigations

Answer 6

Contact Eczema

• Skin patch testing - a disc containing allergens is diluted and applied on the skin for 48 hrs. It is positive if it causes a red raised lesion

Atopic Eczema

• Lab testing e.g. IgE levels