Acute and emergency dermatology Flashcards
What % of body mass of an average person is made up of skin?
10%
List some normal functions of skin
– Mechanical barrier to infection – Temperature regulation – Fluid and electrolyte balance – Vitamin D synthesis – Sensation
List some consequences of skin failure
Sepsis Hypo- and Hyper- thermia Protein and fluid loss Renal impairment Peripheral vasodilation: can lead to cardiac failure
Define erythroderma
A descriptive term rather than a diagnosis
“Any inflammatory skin disease affecting >90% of total skin surface”
What can cause erythroderma?
– Psoriasis – Eczema – Drugs – Cutaneous Lymphoma – Hereditary disorders
How do you manage erythroderma?
- Appropriate setting - ?ITU or burns unit
- Remove any offending drugs
- Careful fluid balance
- Good nutrition
- Temperature regulation
- Emollients – 50:50 Liquid Paraffin:White Soft Paraffin
- Oral and eye care
- Anticipate and treat infection
- Manage itch
- Disease specific therapy; treat underlying cause
What % of inpatients have drug reactions?
2-3%
When do drug reactions usually present on first exposure and second exposure?
Commonly 1-2 weeks after drug
Within 72 hours if re-challenged
What is an example of a mild drug reaction?
Morbilliform exanthem (rash that looks like measles)
Give some examples of dermatological presentations seen following severe drug reactions
Erythroderma
Stevens Johnson Syndrome/Toxic epidermal necrolysis
DRESS
What are some causative drugs to Stevens Johnson Syndrome (SJS) and Toxic Epidermal necrolysis (TEN) reactions?
– Antibiotics
– Anticonvulsants
– Allopurinol
– NSAIDs
How can SJS be differentiated from toxic epidermal necrolysis?
Prodrome - SJS more like flu, TEN more like fever
TBSA affected - SJS <10%, TEN >30%
Age - SJS more common in kids, TEN in adults
Onset time - SJS slower, TEN very rapid
Describe the clinical features of SJS
URI like prodrome: 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
Describe the clinical features of toxic epidermal necrolysis
Often presents with prodromal febrile illness (fever)
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
Describe a positive Nikolskys sign
when slight rubbing of the skin results in exfoliation of the outermost layer.
How do you manage Stevens Johnson syndrome and Toxic epidermal necrolysis?
- Identify and stop culprit drug as soon as possible
- Supportive therapy
- ?High dose steroids
- ?IV immunoglobulins
- ?Anti-TNF therapy
- ?Ciclosporin
Compare the mortality of SJS to toxic epidermal necrolysis
10% (SJS)
30% (TEN)
What is SCORTEN?
SCORTEN - a severity-of-illness scale with which the severity of certain bullous conditions can be systematically determined. It was originally developed for toxic epidermal necrolysis, but can be used with burn victims, sufferers of Stevens-Johnson Syndrome, cutaneous drug reactions, or exfoliative wounds.
What is the mortality risk associated with a SCORTEN score of 0-1?
> 3.2%
What is the mortality risk associated with a SCORTEN score of 2?
> 12.2%
What is the mortality risk associated with a SCORTEN score of 3?
35.3%
What is the mortality risk associated with a SCORTEN score of 4?
> 58.3%
What is the mortality risk associated with a SCORTEN score of 5 or more?
> 90%
What are some long term complications seen in those who have had SJS or toxic epidermal necrolysis?
o Pigmentary skin changes o Scarring o Eye disease and blindness o Nail and hair loss o Joint contactures
Describe erythema multiforme
Hypersensitivity reaction usually triggered by infection
Most commonly HSV, then Mycoplasma pneumonia
Abrupt onset of up to 100s of lesions over 24 hours
– Distal => proximal
– Palms and soles
– Mucosal surfaces (EM major)
– Evolve over 72 hours
Pink macules, become elevated and may blister in centre
• “Target” lesions
• Self limiting and resolves over 2 weeks
• Symptomatic and treat underlying cause
How do you treat erythema multiform?
Self limiting and resolves over 2 weeks
Symptomatic and treat underlying cause (infection)
What does DRESS stand for?
Drug Reaction with Eosinophilia and Systemic Symptoms
Describe Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS)
- Onset 2-8 weeks after drug exposure
- Fever and widespread rash
- Eosinophilia and deranged liver function
- Lymphadenopathy
- +/- other organ involvement
When does DRESS occur following drug exposure?
2-8 weeks after drug exposure
How is DRESS treated?
Stop causative drug
Symptomatic and supportive treatment
• Systemic steroids
• +/- Immunosuppression or immunoglobulins
Describe pemphigus and where on the body it affects
- 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
- Commonly affects mucous membranes
- Ill defined erosions in mouth
- Can also affect eyes, nose and genital areas
Describe pemphigoid
- Antibodies directed at dermo-epidermal junction
- Intact epidermis forms roof of blister
- Blisters are usually tense and intact
What are the differences between pemphigus and pemphigoid?
Pemphigus
o Uncommon
o Middle aged patients
o Blisters very fragile – may not be seen intact
o Mucous membranes usually affected
o Patients may be very unwell if extensive
o Treat with systemic steroids. Dress erosions. Supportive therapies
Pemphigoid
o Common
o Elderly patients
o Blisters often intact and tense
o Even if extensive, patients are fairly well systemically
o Topical steroids may be sufficient if localised; systemic usually required if diffuse
How is pemphigus treated?
Treat with systemic steroids.
Dress erosions.
Supportive therapies
How is pemphigoid treated?
Topical steroids may be sufficient if localised; systemic usually required if diffuse
Describe Erythrodermic psoriasis and Pustular Psoriasis
Can occur without previous history of psoriasis
Common causes:
– Infection
– Sudden withdrawal of oral/potent topical steroid
Rapid development of generalised erythema (redness), +/- clusters of pustules
Fever, elevated WCC
• Exclude underlying infection, bland emollient, avoid steroids
• Often require initiation of systemic therapy
How is Erythrodermic psoriasis and Pustular Psoriasis treated?
- Exclude underlying infection, bland emollient, avoid steroids
- Often require initiation of systemic therapy
What causes Erythrodermic psoriasis and Pustular Psoriasis commonly?
– Infection
– Sudden withdrawal of oral/potent topical steroid
Describe the clinical features of Eczema Herpeticum
Disseminated herpes virus infection on a background of poorly controlled eczema
Monomorphic blisters and “punched out” erosions
– Generally painful, not itchy
Fever and lethargy
How is Eczema Herpeticum treated?
- Treatment dose of Aciclovir
- Mild topical steroid if required to treat eczema
- Treat secondary infection
- Ophthalmology input if peri-ocular disease
- In adults consider underlying immunocompromise
Who are commonly affected by Staphylococcal Scalded Skin Syndrome?
Common in children, can occur in immunocommpromised adults
Describe Staphylococcal Scalded Skin Syndrome
Initial Staph. infection
– May be subclinical
Diffuse erythematous rash with skin tenderness
More prominent in flexures
Blistering and desquamation follows
– Staphylococcus produces toxin which targets Desmoglein 1
Fever and irritability
How is Staphylococcal Scalded Skin Syndrome treated?
Require admission for IV antibiotics initially and supportive care
Generally resolves over 5-7 days with treatment
Describe urticaria
Also known as a Weal or Hive:
– Central swelling of variable size, surrounded by erythema. Dermal oedema
– Itching, sometimes burning
Caused by histamine release into dermis
– Fleeting nature, duration: 1- 24 hours
Whats the difference between acute and chronic urticaria?
Acute - <6 weeks
Chronic - >6 weeks
What are some causes of acute urticaria?
o Idiopathic - 50%
o Infection, usually viral - 40%
o Drugs, IgE mediated - 9%
o Food, IgE mediated – 1%
Whats the most common cause of chronic urticaria?
Idiopathic, 50%
What % of urticaria is caused by infection (usually viral)?
40%
What % of urticaria is caused by IgE mediated drug reactions?
9%
What % of urticaria is caused by IgE mediated food reactions?
1%
How is acute urticaria treated?
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 drugs need to be avoided in urticaria?
Opiates and NSAIDs - exacerbate urticaria
What are some causes of chronic urticaria?
Autoimmune/Idiopathic - 60%
Physical trauma - 35%
Vasculitic - 5%
Rarely a Type 1 hypersensitivity reaction
What is the most common cause of chronic urticaria?
AI/idiopathic
How is chronic urticaria treated?
o 1st line- standard dose of non-sedating H1 antihistamine
o 2nd line – higher dose antihistamine (up to 4X recommended dose) or add in second antihistamine
o 3rd line – consider a second line agent, such as an anti-leukotriene or, if angioedema is present, use tranexamic acid
o 4th line – consider an immunomodulator e.g. omalizumab, ciclosporin
Also identify any triggers and educate on how to avoid it
What are the basic principles of skin failure management?
– Good fluid and electrolyte balance
– Temperature regulation
– Emollients
– Anticipate and treat infection
