Dermatology emergencies

Question 1

Differentiate urticaria and angioedema

Answer 1

Urticaria is swelling of the superficial dermis. Itchy wheals.

Angioedema is swelling of the deep dermis, subcutaneous, and submucosal tissues.

Question 2

Name 4 causes of urticaria and angioedema

Answer 2

Idiopathic
Food
Drugs
Insect bites
Contact - latex
Viral or parasitic infection
Autoimmune
Hereditary

Question 3

What are the common sites of angioedema?

Answer 3

Lips
Tongue
Eyelids

Question 4

What is a life-threatening reaction associated with urticaria?

Answer 4

Anaphylaxis

Question 5

Define anaphylaxis

Answer 5

Rapid and severe systemic hypersensitivity reaction featuring:

• Facial and laryngeal oedema
• Bronchospasm
• Hypotension

Initially may present as urticaria or angioedema.

Question 6

What is the initial treatment for urticaria?

Answer 6

Antihistamines

Question 7

What add-on treatment should be given in severe acute urticaria?

Answer 7

Corticosteroids

also indicated for angioedema

Question 8

What is the initial treatment for anaphylaxis?

Answer 8

Adrenaline

Question 9

What add-on treatment is used in anaphylaxis?

Answer 9

Corticosteroids

Antihistamines

Question 10

What are the commonest causes of anaphylaxis

Answer 10

Food
Drugs
Insect bites

Question 11

What preventative measures are given to anaphylactic patients?

Answer 11

Medic alert bracelet
Self-injectable adrenaline
Antihistamines

Question 12

What are some complications of angioedema and anaphylaxis?

Answer 12

Asphyxia
Cardiac arrest
Death

Question 13

What conditions features discrete tender nodules most commonly on the shins?

Answer 13

Erythema nodosum

Question 14

What is the progression of erythema nodosum?

Answer 14

Appears for 1-2 weeks
Do not ulcerate
Resolve without atrophy or scarring

Question 15

List 3 causes of erythema nodosum

Answer 15

Inflammatory bowel disease
Group A beta-haemolytic strep
Primary TB
Pregnancy
Malignancy
Sarcoidosis
Leprosy

Question 16

Which hypersensitivity reaction presents with typical target shaped lesions?

Answer 16

Erythema multiforme

Question 17

List 2 causes of erythema multiforme

Answer 17

Idiopathic
Herpes simplex virus
Mycoplasma pneumoniae
Drugs

Question 18

Define erythema multiforme

Answer 18

An acute self-limiting hypersensitivity reaction resulting in the development of many red papules of varying shape.

First appears on hands and feet, before spreading proximally.

Question 19

Differentiate erythema multiforme and Stevens-Johnson syndrome

Answer 19

Erythema multiforme: Absent or one mucosal surface

Stevens-Johnson syndrome: Extensive necrosis. Two mucosal surfaces

Question 20

What are the characteristics of Stevens-Johnson syndrome?

Answer 20

Mucocutaneous necrosis at atleast two mucosal sites. Involves <10% of total body surface area. Primarily associated with drugs and infections.

Histology: Epithelial necrosis with few inflammatory cells

Question 21

What is Toxic epidermal necrolysis?

Answer 21

Acute severe extensive necrosis of the skin and mucosal membranes, accompanied with systemic toxicity. Involves >30% of total body surface area. Typically drug-induced.

Histology: Full thickness epidermal necrosis with subepidermal detachment

Question 22

Differentiate Stevens-Johnson syndrome and Toxic epidermal necrolysis

Answer 22

SJS involves <10% of total body surface area

TEN involves >30% of total body surface area

Question 23

Outline the management of erythema multiforme, Stevens-Johnson syndrome, and Toxic epidermal necrolysis

Answer 23

Early recognition and call for help

Full supportive care to maintain haemodynamic equilibrium

Question 24

What are the complications of Stevens-Johnson syndrome and Toxic epidermal necrolysis?

Answer 24

Death, often due to sepsis, electrolyte imbalances, or multi-system organ failure.