Acute and Emergency Dermatology Flashcards
Name some functions of skin which may fail?
Barrier = Sepsis
Thermoregulation = Hyper or Hypothermia
Fluid/Electrolyte Balance = Loss of fluid, renal impairment, protein loss, vasodilation.
Can lead to Cardiac Failure.
What is Erythroderma?
Shows that skin failure has happened BUT IS NOT A DIAGNOSIS ITSELF - wouldnt diagnose someone with erythroderma.
Any inflamm condition which causes redness on >90% of the body = erythrodermic.
Very dangerous in elders.
What are the causes of Erythroderma?
Psoriasis
Eczema
Drugs
Cutaneous lymphoma
Hereditary disorders
What are the principles of management of Skin Failure/Erythroderma?
Admit to ICU/Burns Unit
Remove offending drugs
Maintain fluid balance
Good nutrition (losing lots of protein)
Ensure patient remains at suitable temperature (humidity and temp control)
Emollients - 50:50 liquid paraffin: white soft paraffin
Oral and eye care - to avoid long term effects
Anticipate and treat infection
Manage itch
Disease specific therapy; treat underlying cause (e.g - eczema, psoriasis, cutaneous lymphoma)
When do drug reactions resulting in skin symptoms often occur?
Commonly 1-2 weeks after drug - within 72 hours if re-challenged
What are the mild and severe forms of drug reactions?
Mild - morbilliform exanthem
Severe - Erythroderma, stevens johnson syndrome/toxic epidermal necrolysis, DRESS
What causes the onset of Stevens Johnson Syndrome and Toxic Epidermal Necrolysis?
Secondary to drugs -
–Antibiotics
–Anticonvulsants
–Allopurinol
–NSAIDs
Vital to recognise and treat - stop offending drugs.
What are the clinical features of SJS (Mild)?
Lost Epidermis and crusted erosions.
•Fever, malaise, arthralgia
•Rash
–Maculopapular, target lesions, blisters
–Erosions covering <10% of skin surface
•Mouth ulceration
–Greyish white membrane
–Haemorrhagic crusting
•Ulceration of other mucous membranes
Briefly describe TENS (Severe)?
Severe drug reaction with erythema/ulceration which covers >30% of body
Requires ITU setting, airway support, large haemorrhagic erosions, almost complete skin involvement
What is the clinical presentation of Toxic Epidermal Necrolysis?
Ulceration of mucous membranes
Rash:
–May start as macular, purpuric or blistering
–Rapidly becomes confluent
–Sloughing off of large areas of epidermis – ‘desquamation’ > 30% BSA
–Nikolsky’s sign may be positive - rub finger across skin and it comes off
What is the management for TEN?
Identify and stop culprit drug as soon as possible
Supportive therapy
- ?High dose steroids
- ?IV immunoglobulins
- ?Anti-TNF therapy
- ?Ciclosporin
What score is used to determine the prognosis of TEN?
SCORTEN
- Age >40
- Malignancy
- Heart rate >120
- Initial epidermal detachment >10%
- Serum urea >10
- Serum glucose >14
- Serum bicarbonate <20
Score 5 or more = >90% mortality
What are the long term complications of TEN?
–Pigmentary skin changes
–Scarring
–Eye disease and blindness
–Nail and hair loss
–Joint contactures
What is erythema multiform?
Abrupt onset of 100s of lesions over 24 hours - hypersensitivty reaction usually triggered by infection (HSV and mycoplasma pneumonia)
Think of as diff condition, similar rash to SJS but its due to viral trigger NOT DRUGS. These patients do much better than SJS and TEN patients.
Where are the lesions located in erythema multiforme?
Go from distal to proximal
Start at the palms and the soles
Includes mucosal surfaces
What happens to the lesions over time?
They evolve over 72 hours - pink macules become elevated and may blister in the centre
Resolves over 2 weeks - dont treat
What does DRESS stand for?
Drug reaction with eosinophilia and systemic symptoms
What is the onset of DRESS?
2-8 weeks after drug exposure
What are the clinical featrures of DRESS?
Fever and widespread rash
Eosiniphilia and deranged liver function
Lymphadenopathy
Possible involvement of other organs
What is the management for DRESS?
Stop causative drug
Treat symptoms
Systemic steroids
Possible immunosuppressants or immunoglobulins
Describe Pemphigus?
Split more superficial than in Pemphigoid. Split is in epidermis.
- Antibodies targeted at desmosomes
- Skin – flaccid blisters, rupture very easily
- Intact blisters may not be seen
- Common sites – face, axillae, groins
- Nikolsky’s sign may be +ve
Describe Pemphigoid?
- Antibodies directed at dermo-epidermal junction
- Intact epidermis forms roof of blister
- Blisters are usually tense and intact – have to pop them to get rid of
- Usually older patients who get it
Where are antibodies directed in Pemphigoid?
•Antibodies directed at dermo-epidermal junction
What are the differences between Pemphigus and Pemphigoid?
What are the causes of erythrodermic psoriasis and pustular psoriasis?
Infection
Sudden withdrawal of oral steroids or potent topical steroid
What are the clinical features of Erythrodermic psoriais and Pustular Psoriasis?
- Rapid development of generalised erythema, +/- clusters of pustules
- Fever, elevated WCC
What is the management of erythrodermic psoriasis and pustular psoriasis?
Exclude underlying infection, blsnd emollient and avoid steriods
Often requires initiation of systemic therapy
What causes eczema herpeticum?
•Disseminated herpes virus infection on a background of poorly controlled eczema
What are the clinical features of eczema herpeticum?
•Monomorphic blisters and “punched out” erosions
–Generally painful, not itchy
•Fever and lethargy
What is the treatment for eczema herpeticum?
Treatment dose aciclovir
Mild topical steroid if required to treat eczema
Treat secondary infection
Ophthalmology input if peri-occular disease
In adults consider underlying immunocompromise
What is staphylococcal scalded skin syndrome?
Initial staph infection, may be subclinical (common in children, but can occur in immunocompromised adults)
Diffuse erythematous rash with skin tenderness
Prominent in flexures
Blistering and desquamation follows
What is the disease process of staphylococcal scalded skin syndrome?
Staphylococcus produces a toxin which targets desmoglein 1
Despite the rash and the blistering, what other symptoms does the patient have?
Fever and irritability
What is the treatment for staphylococcal scalded skin syndrome?
Admission for IV antibiotics initially and supportive care
Generally resolves over 507 days with treatment
What is urticaria?
–Central swelling of variable size, surrounded by erythema. Dermal oedema
What causes the itching / brining feeling of urticaria?
Histamine release into the dermis
What is the disease progression of urticaria?
–fleeting nature, duration: 1- 24 hours
What is angioedema?
–Deeper swelling of the skin or mucous membranes
What are the causes of acute urticaria?
Idiopathic
Infection (viral)
Drugs, IgE mediated
Food. IgE mediated
What is the treatment for acute urticaria?
•Oral antihistamine
–Taken continuously
–Up to 4 x dose
- Short course of oral steroid may be of benefit if clear cause and this is removed
- Avoid opiates and NSAIDs if possible (exacerbate urticaria)
What is the definition of chronic urticaria?
History of over 6 weeks
What are the causes of chronic urticaria?
Autoimmune / idiopathic (60%)
Physical (35%)
Vasculitic (5%)
Rarely a type 1 hypersensitvity reaction
What is the management of chronic urticaria?
Describe % of detached epidermis in SJS vs TEN?
<10% = SJS
10-30% = Overlap grey area
>30% = TEN
Name 2 derm presentations which involve blisters?
PEMPHIGUS
PEMPHIGOID
In blistering, at dermal epidermal junction, desmosomes and anchoring proteins are under AI attack, so split appears and epidermis lifts off.
