Acute and Emergency Dermatology Flashcards
What % of body mass does skin make up in the average person?
10%
Consequences of failure of the skin
Sepsis Hyper and hypo thermia Protein and fluid loss Renal impairment Peripheral vasodilation that can occasionally lead to cardiac failure
Definition of erythroderma
Any inflammatory skin disease affecting > 90% of the total skin surface
Causes of erythroderma
Psoriasis Eczema Drugs Cutaenous lymphoma Hereditary disorders
Treatment of erythroderma
ITU / burns unit Remove any offending drugs Careful fluid balance Good nutrition Temp regulation Emollients - 50:50 liquid paraffin : white soft paraffin Oral and eye care Anticipate and treat infection Manage itch Treat underlying cause
When do drug reactions commonly occur?
1 - 2 weeks after drug
Within 72 hours if rechallenged
Mild drug reactions affecting the skin causes what?
Morbilliform exanthem
Severe drug reactions affecting the skin causes what?
Erythroderma
Steven johnstons syndrome / toxic epidermal necrolysis
DRESS
Which of SJS and TEN is less severe?
SJS
What drugs can cause SJS and TENS?
Antibiotics
Anticonvulsants
Allopurinol
NSAIDs
Presentation of SJS
Fever Malaise Arthralgia Rash - maculopapular - target lesions - blisters Mouth ulceration - greyish white membrane - haemorrhagic crusting Ulceration of other mucous membranes
Definition of arthralgia
Joint pain
Presentation of TEN
Prodromal febrile illness Ulceration of mucous membranes Rash - may start at macular, purpuric or blistering - rapidly becomes confluent - desquamation > 30% BSA Nikolsky's Sign may be +ve
Definition of prodromal
Relating to or denoting the period between the appearance of initial symptoms and the full development of a rash and fever
What is desquamation?
Sloughing off large areas of epidermis
Definition of Nikolsky’s sign
Rub the skin and lose the skin surface over the area that you rub
Treatment of SJS / TEN
Stop drug Supportive Possible - high dose steroids - IV immunoglobulins - anti TNF therapy - ciclosporin
Mortality of SJS
10%
Mortality of TEN
30%
What scoring system is used for SJS / TEN?
SCROTEN
What does SCROTEN look at?
Age > 40 Malignancy HR > 120 Initial epidermis detachment >1-% Serum urea >10 Serum glucose >14 Serum bicarbonate <20%
Long term complications of SJS / TEN
Pigmentary skin changes Scarring Eye disease and blindness Nail and hair loss Joint contractures
What is erythema multiforme?
Hypersensivity reaction usually triggered by infection.
Abrupt onset of up to 100s of lesions over 24 hours
2 most common causes of erythema multiforme
HSV most common
Then mycoplasma pneumonia
Presentation of erythema multiforme
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 the centre
- target lesions
How long does erythema multiforme take to resolve?
Over 2 weeks
What does DRESS stand for?
Drug Reaction with Eosinophilia and Systemic Symptoms
Mortality of DRESS
10%
When does DRESS occur?
Onset 2 - 8 weeks after drug exposure
Presentation of DRESS
Fever Widespread rash Eosinophilia Deranged liver function Lymphadenopathy \+/- other organ involvement
Treatment of DRESS
Stop causative drug
Symptomatic and supportive
Systemic steroids
+/- immunosuppression or immunoglobulins
Pathology of pemphigus
Antibodies targeted at desmosomes
Presentation of pemphigus
Flaccid blisters which rupture very easily
Intact blisters may not be seen
May be Nikolsky’s sign +ve
Where do you get the lesions of pemphigus?
Face Axillae Groin Mucous membranes Ill defined erosions in mouth
Pathology of pemphigoid
Antibodies directed at dermo-epidermal junction
Presentation of pemphigoid
Intact epidermis forms the roof of the blister
Blisters are usually tense and in tact
Who gets pemphigus?
Middle aged patients
How common is pemphigus?
Uncommon
Treatment of pemphigus
Systemic steroids
Dress erosions
Supportive therapies
How common is pemphigoid?
Common
Who gets pemphigoid?
Elderly
If extensive disease, how are pemphigus patients?
Very unwell
If extensive disease, how are pemphigoid patients?
Fairly well systematically
Treatment of pemphigoid patients
Topical steroids if localised
Systemic if diffuse
Can erythrodermic psoriasis and pustular psoriasis occur if you haven’t had psoriasis before?
Yes
Common causes of erythrodermic or pustular psoriasis
Infection
Sudden withdrawal of oral steroids or potent topical steriod
Presentation of erythrodermic / pustular psoriasis
Rapid development of generalised erythema
+/- clusters of pustules
Fever
Elevated WCC
Treatment of erythrodermic / pustular psoriasis
Exclude underlying infection
Bland emollient
Avoid steroids
Systemic therapy Often needed
What is eczema herpeticum?
Disseminated herpes virus infection on a background of poorly controlled eczema
Presentation of eczema herpeticum
Monomorphic blisters and "punched out" erosions Generally Painful Not itchy Fever Lethargy
Treatment of eczema herpeticum
Aciclovir
Mild topical steroid if required to treat eczema
Treat secondary infection
Ophthalmology input if peri-ocular disease
If an adult and have eczema herpeticum, what should be considered?
Underlying immunocompromise
Who does staphylococcal scaled skin syndrome (SSSS) occur in?
Children
Immunocompromised adults
Presentation of SSSS
Initial staph infection (may be subclinical) Diffuse erythematous rash Skin tenderness More prominent in flexures Blistering and desquamation follows Fever Irritability
Why does blistering and desquamation occur in SSSS?
Staphylococcus produces toxin which targets desmoglein 1
Treatment of SSSS
IV antibiotics
Supportive care
How long does SSSS take to resolve with treatment?
5 - 7 days
Other names for urticaria
Weal
Hives
What is urticaria?
Central swelling of variable size, surrounded by erythema
Dermal oedema
Presentation of urticaria
Swellings surrounded by erythema
Itching
Sometimes burning
Fleeting nature
Duration of urticaria
1 - 24 hours
What is angioedema?
Deeper swelling of the skin or mucous membranes
Definition of acute urticaria
< 6 week history
Causes of acute urticaria
Idiopathic 50%
Infection, usually viral 40%
Drugs, IgE mediated 9%
Food, IgE mediated 1%
Treatment of acute urticaria
Oral antihistamine
What drugs exacerbate urticaria?
Opiates
NSAIDs
Definition of chronic urticaria
> 6 week history
Causes of chronic urticaria
Autoimmune/idiopathic 60%
Physical 35%
Vasculitic 5%
Rarely type 1 hypersensitivity reaction
Treatment of chronic urticaria
Omalizumab
What is Omalizumab?
Monoclonal antibody to IgE
What complications are monitored for in an inpatient with erythroderma?
Dehydration
Infection
High output heart failure
Bullous pemphigoid vs pemphigus vulgaris
Bullous pemphigoid - NO mucosal involvement
Pemphigus vulgaris - mucosal involvement
Children with new onset purpura need to be admitted and tested to exclude what two conditions?
ALL
Meningococcal septicaemia
When should superficial dermal burns be referred to secondary care?
> 3% TBSA adults
2% TBSA children
Also if involve face, hands, feet, perineum, genitalia, any flexure, circumferential burns of the limbs, torso or neck
