Allergic skin conditions

Question 1

Give 6 features of eczematous skin presenting in atopic dermatitis

Answer 1

Dry
Itchy
Erythematous
Scaling
Vesicles
Lichenification

Question 2

Which sites are usually involved in atopic dermatitis?

Answer 2

Flexor surfaces: ANTECUBITAL + POPLITEAL fossae

Extensor surfaces of hands

Question 3

Which conditions form the atopic triad?

Answer 3

Asthma
Allergic rhinitis
Atopic Dermatitis

Question 4

What is the atopic triad linked to?

Answer 4

Allergen triggered IgE mast cell activation

Question 5

Give 3 risk factors for atopic dermatitis

Answer 5

Atopic triad
FH
<5

Question 6

Ix for atopic dermatitis

Answer 6

Clinical dx

Question 7

What additional Ix may be performed in suspected atopic dermatitis?

Answer 7

Allergen testing (IgE levels, Skin-prick/Patch)
Skin biopsy

Question 8

Tx for acute flair of atopic dermatitis

Answer 8

Emolient
Topical corticosteroid (intermittent/ in those not controlled by emollient)
Topical/ Oral Abx (if infection)

Question 9

Tx for chronic/ relapsing atopic dermatitis

Answer 9

Emolient
Topical low/mid potency corticosteroid (Hydrocortisone)
+/- topical calcineurin inhibitor (Pimecrolimus)

Question 10

Give 3 systemic tx options for atopic dermatitis

Answer 10

Phototherapy
Non-corticosteroid immuno-modulating drug
Systemic corticosteroids

Question 11

2 types of contact dermatitis

Answer 11

Irritant: direct toxicity, can occur without prior sensitisation
Allergic: Delayed hypersensitivity, requires prior sensitisation

Question 12

Onset of contact dermatitis

Answer 12

Irritant: Acute onset (mins-hours)
Allergic: 24-72hrs post exposure in sensitised individual

Question 13

3 features of presentation in contact dermatitis

Answer 13

Itchy red papules
Occupational history of exposure
Distribution in areas of exposure to irritant/ allergy

Question 14

Ix for contact dermatitis

Answer 14

Clinical dx

Patch testing if unsure

Question 15

Tx for irritant contact dermatitis

Answer 15

Avoidance of irritant

Moisturiser/ top corticosteroid to resolve dermatitis

Question 16

Tx for allergic contact dermatitis

Answer 16

Avoidance of allergen

Topical corticosteroid

Question 17

What is vitiligo?

Answer 17

Acquired loss of melanocytes in circumscribed areas of epidermis, resulting in complete depigmentation of affected skin.

Question 18

What immunological process is involved in vitiligo?

Answer 18

T-cell-mediated destruction of melanocytes

Question 19

Give 3 risk factors for vitiligo

Answer 19

FH
Age <20
Associated AI condition

Question 20

Which 6 AI conditions are associated to vitiligo?

Answer 20

AI Thyroid disease
Pernicious anaemia
SLE
Alopecia areata
T1DM
Addison's disease

Question 21

3 features of vitiligo presentation

Answer 21

Asymptomatic
Flat, non-scaly, clearly demarcated areas of whiteness
Often bilateral + symmetrical

Question 22

Ix for vitiligo

Answer 22

Clinical dx
Screen for associated AI diseases
Wood’s light test (exclude fungal infection)

Question 23

3 minimally invasive Mx options for vitiligo

Answer 23

Protect against sun burn
Minimise skin injury (as increased likelihood of new patches if damaged)
Cosmetic camoflauge creams

Question 24

3 Tx options for vitiligo

Answer 24

Topical corticosteroids
Topical calcineurin inhibitors
Phototherapy

Question 25

Difference between skin prick + patch tests

Answer 25

Prick + serum IgE: detect type I reactions related to food + aeroallergens
Patch: detects type IV reactions for contact dermatitis.

Question 26

Which viruses cause eczema herpeticum?

Answer 26

HSV

Cocksackie (rare)