Drug-related and immune-mediated skin conditions

Question 1

What life-threatening skin conditions are you aware of?

Answer 1

Infective:

• necrotising fasciitis
• Toxic shock syndrome

Drug-related:

• SJS/TEN
• DRESS syndrome (drug, rash, eosinophilia and systemic symptoms syndrome)

Immune-mediated:

• Erythema multiform
• Pemphigus vulgaris

Inflammatory:

• acute generalised pustular psoriasis
• erythroderma (exfoliative dermatitis)

Question 2

What is Stevens-Johnson syndrome and toxic epidermal necrolysis?

Answer 2

SJS and TEN are a spectrum of acute severe, life-threatening skin reactions characterised by:

• prodrome within 4-28 days of sore throat and fever
• rash (macules followed by blistering)
• mucocutaneous involvement and desquamation and necrosis
• organ dysfunction

Question 3

What are the causes of SJS/TEN?

Answer 3

Drugs:

• sulphonamides and beta lactam abx
• allopurinol, NSAIDs, anticonvulsants

Infection:

• CMV
• mycoplasma

Graft vs host disease:
- often severe and fatal

Question 4

How are SJS and TEN differentiated?

Answer 4

SJS <10% TBSA
TEN/SJS overlap 10-30% TBSA
TEN >30% TBSA

Question 5

What is the management of SJS TEN?

Answer 5

• Removal of precipitant
• supportive care (may develop MOF)
• discuss with Burns centre
• topical antiseptics
• often IV steroids +/- IVIg +/- ciclosporin are used but not strong evidence of benefit

Question 6

What is the mortality risk of SJS/TEN?

Answer 6

Up to 30% from drug related. Mortality very high in GvHD.

Question 7

What are the complications of SJS/TEN?

Answer 7

Septic shock
MOF
gastrointestinal perforation
renal failure
thromboembolic phenomena

Question 8

What is DRESS syndrome?

Answer 8

Drug rash eosinophilia and systemic symptoms syndrome.
It is a severe life-threatening condition.
Caused by anticonvulsants and allopurinol most commonly. Other causes include NSAIDS, antimicrobials and antivirals.
Characterised by a longer latency period of 2-6 weeks and the morbilliform rash.
Most common extracutaneous involvement is lymphatics, and liver.
Has a mortality of around 10%.
Mx includes:
- removal of causative agent
- IV steroids
- supportive care

Question 9

What are the causes of eosinophilia and rash?

Answer 9

CHINA

C - Connective tissue disease/Churg-strauss (EGPA)
H - Helminth infection
I - idiopathic
N - neoplastic (typically lymphoma)
A - Allergic reaction/Asthma