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OSCE 446: Widespread Skin Loss
Question No. 2
Q: What do you consider the most likely diagnosis? (1 marks)
Answer No. 2
Given the mucosal lesions and the large body surface area involved the most likely diagnosis is Toxic Epidermal Necrolysis 1
1
Question No. 3
Q: What is the difference between SJS and TEN? (2 marks)
Answer No. 3
- SJS and TEN are variants of the same disease spectrum but distinguished chiefly by severity
- SJS is the less severe form, affecting <10% total body surface area (TBSA) 1
- TEN is more severe and affects >30% TBSA 1
- Cases that affect 10–30% are referred to as SJS/TEN overlap
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Question No. 4
Q: Give 4 functions of skin relevant to critical illness? (4 marks)
Answer No. 4
Protection
- Barrier function of stratum corneum protects against environmental, chemical, and microbial hazards 1
- Limitation of inward and outward passage of water and electrolytes ensures the conservation of the internal milieu 1
- vDurability and elasticity of dermis contributes to protection against physical injury 1
- Melanin production protects against ultra-violet radiation
Regulation
- Temperature homeostasis is maintained by alteration of skin blood flow, sweating, and pilo-erection 1
- Minor role in maintaining fluid balance by avoiding excessive evaporative water loss that would otherwise cause dehydration and cooling
Immune
- Dynamic role in innate and acquired defense systems 1
Metabolic
- Role in Vitamin D synthesis 1
- Capability in transformation of some drugs 1
Neurosensory
- Terminal fibres of sensory nerves and specialized sensory receptors lying within the dermis enable skin to act as a large sensory organ 1
Social
- Visible portion of body covering
4
Question No. 5
Q: What are the common causes of SJS / TEN? (4 marks)
Answer No. 5
- Drugs (Most common, 4-28 days after initiation) 1
- Allopurinol
- Anticonvulsants
- Cotrimoxazole
- 'Sulfa' drugs
- Oxicam NSAIDs
- Nevirapine
- Infections 1:
- HIV
- CMV
- Mycoplasma
- Malignancy 1
- Bone marrow transplant 1
- Genetic predisposition
4
Question No. 6
Q: What are the non-cutaneous (or mucocutaneous) manifestations of SJS / TEN? (4 marks)
Answer No. 6
Skin
Initial Phase:
- Erythematous, dusky red, flat macules
- Lesions symmetrically distributed on face, trunk and limbs
Late Phase:
- Lesion coalesce to form flaccid blisters
- Epidermal detachment
Mucous Membranes
- Eyelid oedema, redness and discharge
- Buccal erosive haemorrhagic lesions, white pseudomembranous crust
- Crust on lips
- Genital erosive haemorrhagic lesions, painful urination
Extracutaneous Sites
- Respiratory Tract: Respiratory distress 1
- GI Tract: Nausea 1, diarrhoea 1, malabsorption 1, colonic perforation 1
- Renal Tract: Proteinuria 1, haematuria 1
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Question No. 7
Q: Which scoring system is recognised for determining severity and prognosis in SJS / TEN? (1 marks)
Answer No. 7
- The SCORTEN score1 is a validated scoring system to predict mortality
1
Question No. 8
Q: Name 4 components of the Scorten system? (2 marks)
Answer No. 8
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This should be scored within 24 hours of admission.
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Age >40 0.5
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Malignancy 0.5
-
Initial area greater >10% 0.5
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Heart rate >120 0.5
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Serum urea >10 0.5
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Serum glucose >14 0.5
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Serum bicarbonate <20 0.5
Max 2
-
Score
Predicted Mortality (%)
0-1
3.2
2
12.1
3
35.3
4
58.3
5 or more
90
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Question No. 9
Q: When would you suggest surgical skin debridement in SJS / TEN? (2 marks)
Answer No. 9
- Surgical debridement may be indicated, particularly if:
- Local sepsis / subepidermal pus1
- Extensive epidermal detachment1
2