Toxic Epidermal Necrolysis

2. ► What is T.E.N.?
► Causes
► Clinical Features
► Differential Diagnosis
► Investigations
► Management
► Complications
► Prognosis

3. ► Definition:
► Toxic = “pertaining to, due to or the nature of a poison or toxin, manifesting
the symptoms of severe infection”
► Epidermal = “pertaining to or resembling the epidermis”
► Necrolysis = “separation or exfoliation of tissue due to necrosis”
► Rare
► Life threatening
► Drug induced
► adverse drug reaction: 5-15% drug treatments
► cutaneous reactions: most common
► morbilliform type: most common
► symmetrical, erythematous rash, macules & papules, lasts few days
► can proceed to serious cutaneous reactions:
► serum sickness
► hypersensitivity syndrome
► T.E.N.

4. ► Mucocutaneous reaction
► widespread erythema
► necrosis
► bullous detachment of epidermis & mucous membranes
► GI haemorrhage
► respiratory failure
► genitourinary complications
► Incidence: 0.4-1.2 cases/million population/year
► Affects all ages
► Mortality rate: 30-40%

5. ► Adverse drug reaction
► over 100 drugs implicated
Commonest Causative Drugs
Sulphonamide antibiotics
Anticonvulsants
NSAIDs
Allopurinol
Corticosteroids
Newest Causative Drugs
Nevirapine (antiretroviral)
Lamatrogine
► Other causes:
► immunisations; bone marrow transplants; solid organ transplants

6. ► Prodromal phase: 1 – 14 days
► flu-like symptoms
► Inflammation:
► eyelids
► conjunctiva
► Tenderness:
► oral mucosa
► general cutaneous
► Generalised macular erythma:
► progresses to flaccid blisters and bullae
► join to form large bullae
► large areas of epidermis are “sloughed off”
► Mucous membranes often involved
► usually 1-3 days earlier then skin lesions
► eyes; oropharynx; respiratory tract; GI tract; genital tract; anus
Rapid progression over days. 10 – 100% of body’s surface area involved.
Discomfort
Pain
Fever
Sore throat
Cough
Malaise

8. Differential Diagnosis of T.E.N.
Burns
Conjunctivitis
Ulcerative keratitis
Staphylococal Scalded Skin Syndrome
Stevens-Johnson Syndrome (S.J.S.)
Toxic Shock Syndrome
Exfoliative dermatitis
Erythema multiforme
Pemphigus
S.J.S. and T.E.N. Are very similar in cause, severity, clinical features and
variability. They only really differ in the extend of skin detachment and mortality –
both being larger in T.E.N.

9. ► MICROBIOLOGY
► blood culture
► MSU
► swabs; including MRSA screening swabs
► GENERAL
► FBC
► ESR
► U&E and creatinine
► LFTs
► Albumin
► Glucose
► Calcium
► CRP
► Urine dipstick (protein & blood)
► IF INDICATED
► coagulation studies
► CXR

10. ► MAINLY SUPPORTIVE
► discontinue causative drug
► burns unit
► skin care; protect skin from infection
► monitor fluid and electrolyte balance
► nutritional support
► analgesics (may need oral/iv morphine)
► eye care; lubrication with chloramphenicol
► SCORTEN assessment

11. ► Ocular
► conjunctivitis
► vesiculation
► corneal ulceration/scarring
► uveitis
► synchiae
► pseudomembrane formation
► blindness
► Cutaneous
► scarring
► hypopigmentation
► hyperpigmentation
► Mucous membranes
► scarring
► oesophageal, bronchial, anal and vaginal strictures

12. ► SCORTEN assessment; first 24 hours after admission
Factors associated with poor prognosis
Age > 40 years
Heart rate > 120 bpm
Malignancy
Day 1 blistering affecting > 10% body surface area
Urea > 10 mmol/l
Bicarbonate < 20 mmol/l
Glucose > 14 mmol/l
SCORTEN score Mortality Rate
0-1 3%
2 12%
3 35%
4 58%
>5 90%
Overall
mortality
around
30%

13. ► Bastuji-Garin, S., Fouchard, N., Bertocchi, M., Roujeau, J-C., Revuz, J. &
Wolkenstein, P. (2000). SCORTEN: A severity-of-illness scor for toxic epidermal
necrolysis, J. Invest. Dermatol., 115(2): 149-153.
► Dictionary of Cell and Molecular Biology
► Devkaran, A. & Gupta, S. (2008) Toxic Epidermal Necrolysis, Student BMJ;
16:168-170.
► www.wsh.nhs.uk/dermatology
► www.medscape.com
► www.adr.org.uk
► www.pathconsultddx.com