Eczema and urticaria

Question 1

Atopic patients have elevated serum levels of which immunoglobulin?

Answer 1

IgE

Question 2

Describe the clinical features of atopic dermatitis?

Answer 2

Ill-defined erythematous scaly patches occur on the face and in flexural sites. Scratching and rubbing lead to infection, skin thickening and lichenification

Question 3

What are the principles of therapy for atopic dermatitis?

Answer 3

Moisturise the skin with emollients and minimise itching with oral antihistamines

Question 4

Name some specific treatments for atopic dermatitis?

Answer 4

Tar
Steroids
Calcineurin inhibitors
Antibiotics for complicating infection

Question 5

What is the treatment for eczema herpeticum?

Answer 5

Systemic aciclovir

Question 6

What is lichen simplex?

Answer 6

Eczema in response to repeated trauma or scratching

Question 7

What is Nodular prurigo?

Answer 7

Widespread version of lichen simplex

Question 8

Where does eczema stasis usually present?

Answer 8

Inner shin and medial malleolus

Question 9

What is asteatotic eczema?

Answer 9

Glazed “crazy-paving” effect which occurs on the legs of elderly patients where there is dry skin - responds to emollients and topical steroids

Question 10

What is discoid eczema?

Answer 10

Itchy, symmetrical, coin-shaped lesions on the extensor surfaces of the limbs and feet - treated with emollients, topical steroids and antihistamines

Question 11

What is pompholyx?

Answer 11

Acute vesicular eczema of the palms and soles - treated with potassium permanganate soaks, and topical or systemic steroids. Pompholyx often recurs

Question 12

What is seborrhoeic dermatitis?

Answer 12

A common, mildly itchy, scaly, red rash with a predilection for the scalp, face, chest, back, axillae and groins. It is an abnormal cutaneous reaction to commensal Pityrosporum yeasts. It may occur in HIV infection and Parkinson’s disease - treatment with topical steroids plus an anti-yeast agent (e.g. imidazole). When the scalp is affected (dandruff), ketoconazole or selenium sulphide shampoo can be helpful

Question 13

What type of cell-mediated immunological reaction is allergic contact dermatitis?

Answer 13

Type IV

Question 14

What is the principal investigation for allergic contact dermatitis?

Answer 14

Patch testing

Question 15

Which drugs can cause/exacerbate common urticaria?

Answer 15

Aspirin
Codeine
Morphine
NSAIDS

Question 16

What is urticaria?

Answer 16

Itchy erythematous wheals (i.e. skin swellings resulting from leaky capillaries). Very common and results from mast cell degranulation

Question 17

What type of immunological reaction is urticaria?

Answer 17

Type I

Question 18

What percent of patients with urticaria have idiopathic urticaria?

Answer 18

70%

Question 19

What is the differential diagnosis when the patient has a suspected urticaria?

Answer 19

Insect bites
Prodromal pemphigoid
Toxic erythema
Erythema multiforme

Question 20

What investigations should be performed if something other than acute idiopathic urticaria is suspected?

Answer 20

Full blood count
Eosinophil count
Erythrocyte sedimentation rate
Thyroid autoantibodies
Thyroid function
Renal function
Liver function
Complement levels examined
Stool sample for ova, cysts and parasites

Question 21

What medication can be given for urticaria?

Answer 21

High doses of non-sedating anti-H1-receptor histamines by day supplemented by sedating antihistamines at night

Question 22

What is the treatment of acute laryngeal angioedema and anaphylaxis?

Answer 22

IM injection of 0.5ml of 1:1000 adrenaline (epinephrine) 500ug is the recommended treatment. Fixed dose (300ug) ‘pen’ injections are available for at-risk individuals

Question 23

When is urticarial vasculitis suspected?

Answer 23

If urticarial lesions last >24 hours and resolve with purpura

Question 24

What diseases is urticarial vasculitis associated with?

Answer 24

Systemic lupus erythematosus
Hepatitis B
Hepatitis C

Question 25

When there is a family history and angioedema what is suspected and what is the pathophysiology?

Answer 25

Hereditary angioedema (HAE) caused by congenital (autosomal dominant) deficiency of C1 esterase inhibitor

Question 26

What findings during an attack are highly suspicious of HAE and how can this be confirmed?

Answer 26

Normal C3 and absent C4 and can be confirmed by measurement of total and functional C1 esterase inhibitor levels

Question 27

How can acute attacks of HAE be treated?

Answer 27

Purified C1 esterase inhibitor or icatibant, a bradykinin antagonist