Dermatological Emergencies Flashcards
(21 cards)
Toxic Epidermal Necrolysis (TEN): Definition
Toxic epidermal necrolysis (TEN) is a potentially life-threatening skin disorder that is most commonly seen secondary to a drug reaction. In this condition the skin develops a scalded appearance over an extensive area.
Some authors consider TEN to be the severe end of a spectrum of skin disorders which includes erythema multiforme and Stevens-Johnson syndrome.
Toxic Epidermal Necrolysis (TEN): Features
- Systemically unwell e.g. pyrexia, tachycardic
- Positive Nikolsky’s sign: the epidermis separates with mild lateral pressure
Toxic Epidermal Necrolysis (TEN): Drugs known to induce TEN
- phenytoin
- sulphonamides
- allopurinol
- penicillins
- carbamazepine
- NSAIDs
Toxic Epidermal Necrolysis (TEN): Management
- stop precipitating factor
- supportive care, often in intensive care unit
- intravenous immunoglobulin has been shown to be effective and is now commonly used first-line
- other treatment options include: immunosuppressive agents (ciclosporin and cyclophosphamide), plasmapheresis
Steven-Johnson syndrome: Definition
Stevens-Johnson syndrome is a rare, serious disorder of your skin and mucous membranes. It’s usually a reaction to a medication or an infection.
Often, it begins with flu-like symptoms, followed by a painful red or purplish rash that spreads and blisters. Then the top layer of the affected skin dies, sheds and then heals.
Stevens-Johnson syndrome: Symptoms
- Fever
- Unexplained widespread skin pain
- A red or purple skin rash that spreads
- Blisters on your skin and the mucous membranes of your mouth, nose, eyes and genitals
- Shedding of your skin within days after blisters form
Stevens-Johnson syndrome: Preceding symptoms
If you have Stevens-Johnson syndrome, several days before the rash develops you may experience:
- Fever
- Sore mouth and throat
- Fatigue
- Cough
- Burning eyes
Stevens-Johnson syndrome: Causes
Stevens-Johnson syndrome is a rare and unpredictable reaction. Your doctor may not be able to identify its exact cause, but usually the condition is triggered by a medication or an infection.
A reaction to medication may start while you’re using it or up to two weeks after you’ve stopped using it.
Stevens-Johnson syndrome: MEDICATION and THERAPY causes
Drugs that can cause Stevens-Johnson syndrome include:
- Anti-gout drugs (e.g. allopurinol)
- Anticonvulsants and antipsychotics
- Pain relievers (e.g. ibuprofen, naproxen sodium)
- Antibiotics e.g. penicillin
Stevens-Johnson syndrome: INFECTIOUS causes
Infections that can cause Stevens-Johnson syndrome include:
- Herpes virus (herpes simplex or herpes zoster)
- Pneumonia
- HIV
- Hepatitis A
Stevens-Johnson syndrome: RISK factors
Factors that increase your risk of developing Stevens-Johnson syndrome include:
- HIV infection
- A weakened immune system
- A history of Stevens-Johnson syndrome
- A family history of Stevens-Johnson syndrome.
- The HLA-B*1502 gene
Stevens-Johnson syndrome: Complications
- Secondary skin infection (cellulitis)
- Blood infection (sepsis)
- Eye problems
- Lung involvement
- Permanent skin damage
Stevens-Johnson syndrome: Prevention
- Consider genetic testing before taking certain drugs.
2. If you’ve had SJS - avoid the medication that triggered it.
Erythema multiforme: Definition
Erythema multiforme is a hypersensitivity reaction which is most commonly triggered by infections. It may be divided into minor and major forms.
Previously it was thought that Stevens-Johnson syndrome (SJS) was a severe form of erythema multiforme. They are now however considered as separate entities.
Erythema multiforme: Features
- target lesions
- initially seen on the back of the hands / feet before spreading to the torso
- upper limbs are more commonly affected than the lower limbs
- pruritus is occasionally seen and is usually mild
Erythema multiforme: Causes
- viruses: herpes simplex virus (the most common cause), Orf*
- idiopathic
- bacteria: Mycoplasma, Streptococcus
- drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, oral contraceptive pill, nevirapine
- connective tissue disease e.g. Systemic lupus erythematosus
- sarcoidosis
- malignancy
Erythema Multiforme Major
The more severe form, erythema multiforme major is associated with mucosal involvement.
Necrotising fasciitis: Definition
Necrotising fasciitis is a medical emergency that is difficult to recognise in the early stages.
Necrotising fasciitis: Classification
It can be classified according to the causative organism:
TYPE 1: is caused by mixed anaerobes and aerobes (often occurs post-surgery in diabetics). This is the most common type
TYPE 2: is caused by Streptococcus pyogenes
Necrotising fasciitis: Features
- acute onset
- painful, erythematous lesion develops
- often presents as rapidly worsening cellulitis with pain out of keeping with physical features
- extremely tender over infected tissue
Necrotising fasciitis: Management
- urgent surgical referral debridement
- intravenous antibiotics
