Eczema

Question 1

What is eczema caused by? (3)

Answer 1

Genetics: filaggrin expression defects (chromosome 1)
Immune factors
Atopy

Question 2

Describe the pathophysiology of eczema. (3)

Answer 2

1. Skin barrier defect
2. This causes increased skin permeability
   a. This causes inflammation and oedema
3. This causes decreased antimicrobial function
   a. This causes increased susceptibility to infection

Question 3

List 7 types of eczema.

Which ones are endogenous, and which ones are exogenous?

Answer 3

ENDOGENOUS:
Atopic eczema
Seborrhoeic eczema
Discoid eczema
Varicose/gravitational/stasis eczema
Pompholyx eczema

EXOGENOUS:
Contact dermatitis
Photoreactions

Question 4

Describe the clinical features of atopic eczema. (4)

Answer 4

Itchy, vesicular rash
Lichenification
Underlying erythema
Ulceration/exfoliation (due to scratching)

Question 5

Describe the distribution of atopic eczema. (3)

Answer 5

Poorly defined areas
Face
Flexor surfaces

Question 6

List 4 complications of atopic eczema. Give some examples where relevant.

Answer 6

Bacterial infection (e.g. staph. aureus)
Viral infection (e.g. molluscum contagiosum, viral warts, eczema herpeticum)
Growth retardation
Psychological impact

Question 7

List 4 conditions associated with atopic eczema.

Answer 7

Asthma
Hay fever
Allergy
Conjuctivitis

Question 8

What causes seborrhoeic eczema?

Describe the typical distribution. (4)

Answer 8

Pityrosporum ovale (yeast) infection

DISTRIBUTION:
Scalp
Eyelids
Nostrils
Lips

Question 9

What is seborrhoeic eczema associated with? (2)

Answer 9

Malassezia yeasts

HIV

Question 10

Describe the clinical features of discoid eczema. (1)

Describe the typical distribution. (1)

What is discoid eczema associated with? (1)

Answer 10

Round lesions

Mainly on limbs

Associated with: alcohol misuse

Question 11

Describe the clinical features of varicose/gravitational/stasis eczema. (2)

Describe the typical distribution. (1)

Answer 11

Itchy, vesicular rash
Leg ulcers

Distribution: skin over large veins (esp. legs)

Question 12

What is varicose eczema associated with? (2)

Answer 12

Peripheral vascular disease

Venous insufficiency

Question 13

Describe the pathophysiology of varicose eczema. (3)

Answer 13

1. Underlying venous disease causes incompetence of deep perforating veins
2. This causes increased hydrostatic pressure, causing venodilation
3. Venodilation causes the overlying skin to be stretched
   a. This causes eczema over affected veins
   b. This may cause leg ulceration

Question 14

Describe the clinical features of pompholyx eczema. (1)

What is the typical distribution? (1)

Answer 14

Itchy, vesicular rash

Distribution: palms/soles

Question 15

Describe the pathophysiology of contact dermatitis. (1)

Answer 15

1. Type 4 (delayed) hypersensitivity reaction, mediated by mast cells

Question 16

Give 5 examples of allergens which might cause contact dermatitis.

Answer 16

Nickel
Chromate (e.g. cement)
Cobalt
Colophony (e.g. glue, plasters)
Fragrance

Question 17

What can cause photoreactions? (1)

Answer 17

Allergens

Drug reactions

Question 18

How would you manage atopic eczema? (8)

Answer 18

TOPICAL THERAPIES:
Emollients
Topical steroids
Bandages (to stop scratching)

SYSTEMIC THERAPIES:
Sedative antihistamines
Antibiotics/antivirals (if secondary infection)

LIFESTYLE FACTORS:
Avoid exacerbating factors
Education for parents/children
Information about support (e.g. National Eczema Society)

Question 19

How would you manage seborrhoeic eczema? (4)

Answer 19

Medicated anti-yeast shampoo (conatining ketoconazole, e.g. Nizoral)
Antimicrobial creams
Mild steroid creams
Moisturisers

Question 20

How would you manage varicose eczema? (4)

Answer 20

Emollients
Mild-moderate topical steroids
Compression bandages/stockings
Surgical correction of venous disease