Acute and Emergency Dermatology Flashcards
What are the normal functions of the skin and consequences of failure?
Mechanical barrier to infection - sepsis
Temperature regulation - hypo or hyperthermia
Fluid and electrolyte balance - protein + fluid loss, renal impairment and peripheral vasodilation
What is erythroderma?
A descriptive term rather than diagnosis
Any inflammatory skin disease affecting more than 90% of total skin surface
What are the causes of erythroderma?
Psoriasis, eczema, drugs, cutaneous lymphoma, hereditary disorders and unknown
What are the principles of management for erythroderma?
Remove any offending drugs, careful fluid balance, good nutrition, temp. regulation, emollients, oral and eye care, anticipate and treat infection, manage itch and disease specific therapy
What is a type of mild drug reactions affecting the skin?
Morbilliform exanthem
What are some types of severe drug reaction affecting the skin?
Erythroderma, Stevens Johnson Syndrome/ Toxic epidermal necrolysis and DRESS
Describe Stevens Johnson syndrome/ toxic epidermal necrolysis
2 conditions which are part of the same spectrum - TEN is more severe with more than 30% of skin affected
Rare
Secondary to drugs
Can be delayed onset
What drugs can Stevens Johnson Syndrome/ Toxic Epidermal Necrolysis be secondary to?
Antibiotics, anticonvulsants, allopurinol and NSAIDs
What is the surface of epidermal detachment in SJS and TEN?
SJS - Under 10% epidermal detachment
SJS-TEN overlap - 10-30%
TEN - over 30%
What are the clinical features of SJS?
Fever, malaise, arthralgia, rash ( macropapular, target lesions and blisters), mouth ulceration and ulceration of other mucous membranes
Describe toxic epidermal necrolysis presentation
Often presents with prodromal febrile illness
Ulceration of mucous membranes
Rash - may start as macular, purpuric or blistering, rapidly becomes confluent and sloughing off large areas of epidermis
What is the management for SJS and TEN?
Identify and stop culprit drug as soon as possible
Supportive therapy
How is prognosis of SJS/ TEN calculated?
SCORTEN score
Age >40, malignancy, heart rate >120, initial epidermal detachment >10%, serum urea >10, serum glucose >14 and serum bicarbonate <20
What are the long term complications of SJS or TEN?
Pigmentary skin changes, scarring, eye disease + blindness, nail + hair loss and joint contractures
What is erythema multiforme?
Hypersensitivity reaction usually triggered by infection - most commonly HSV then mycoplasma pneumonia
Abrupt onset up to 100s of lesions on body over 24hrs
Self limiting and resolves in 2 weeks
Symptomatic and treat underlying cause
What is the presentation of erythema multiforme?
Distal to proximal
Palms and soles
Mucosal membranes
Evolves over 72hrs - pink macules and my blister in centre
What does DRESS stand for?
Drug reaction with eosinophilia and systemic symptoms
Describe DRESS
Mortality up to 10%
Onset between 2-8 weeks after drug exposure
Fever and widespread rash
Eosinophilia and deranged liver function
Lymphadenopathy and other organ involvement
What is the treatment for DRESS?
Stop causative drug
Symptomatic and supportive
Systemic steroids
Maybe immunosuppression or immunoglobulins
What are the clinical features of pemphigus?
Antibodies targeted at desmosomes
Skin - flaccid blisters and rupture very easily
Common sites - face, axillae and groins
Nikolsky’s sign may be +
Where else can pemphigus also affect?
Commonly affects mucous membranes
Ill defined erosions in mouth
Can also affect eyes, nose and genital areas
How is pemphigus and pemphigoid diagnosed?
Immunofluorescence skin biopsy is gold standard
Describe pemphigoid
Antibodies directed at dermo-epidermal junction
Intact epidermis forms roof of blisters
Blisters are usually tense and intact
What are the main characteristics of pemphigus?
Uncommon, middle age, blisters are fragile, mucous membranes usually affected, may be unwell if extensive and treat with systemic steroids + dress erosions
