Emergency dermatology Flashcards
(40 cards)
What is the essential management of dermatological emergencies?
Full supportive care (A-E)
Withdrawal of precipitants
Management of associated complications
Specific treatment
What can cause urticaria/angioedema/anaphylaxis?
Idiopathic Food e.g. nuts, sesame, shellfish, dairy products Contrast media Drugs -NSAIDs -Morphine -ACEi etc Insect bites Contact e.g. latex Viral or parasitic infection Autoimmune Hereditary (some cases of angioedema)
What is urticaria?
Local increase in permeability of capillaries/small venules
Several inflammatory mediators (inc. prostaglandins, leukotrienes, chemotactic factors), esp histamine from skin mast cells are major mediators (may be induced by immunological and non-immunological mechanisms)
How does urticaria present?
Swelling of superficial dermis, raising epidermis
Itchy wheals
How does angioedema present?
Deeper swelling involving dermis and subcut tissues
Swelling of tongue and lips
How does anaphylactic shock present?
Bronchospasm
Facial and laryngeal oedema
HNT
May also present with urticaria and angioedema
What is the management for urticaria?
Antihistamine
What is the management for severe urticaria/angioedema?
Corticosteroids
What is the management of anaphylaxis?
Adrenaline
Corticosteroids
Antihistamines
What are the complications of
a) Urticaria?
b) angioedema/anaphylaxis?
a) normally uncomplicated
b) asphyxia, cardiac arrest, death
What is erythema nodosum?
Hypersensitivity response to variety of stimuli
What are the causes of erythema nodosum?
Group A B-haemolytic strep Primary TB Pregnancy Malignancy Sarcoidosis IBD Chlamydia Leprosy
How does erythema nodosum present?
Discrete tender nodules, may become confluent
Lesions continue to appear for 1-2w, leave bruise like discolouration as resolve
Lesions don’t ulcerate, resolve without atrophy or scarring
Shins most common site
What is erythema multiforme?
Acute, self-limiting inflammatory condition
Often of unknown cause but HSV often main precipitant (other infections and drugs are also causes)
Mucosal involvement absent or limited to just one mucosal surface
What is Stevens-Johnson syndrome?
Mucocutaneous necrosis with at least two mucosal sites involved (skin involvement may be limited or extensive)
Drugs/combinations of infections and drugs are main associations
Epithelial necrosis with few inflammatory cells seen on histopathology
Extensive necrosis distinguishes Stevens-Johnson from erythema multiforme
Stevens-Johnson may have features overlapping with toxic epidermal necrolysis, including prodromal illness
What is toxic epidermal necrosis?
Usually drug-induced
Acute severe disease characterised by extensive skin and mucosal necrosis with systemic toxicity
Histopath shows full thickness epidermal necrosis with subepidermal detachment
How are erythema multiforme/Stevens-Johnson/toxic epidermal necrosis managed?
Early recognition and call for help
Supportive care for haemostasis
What complications are associated with erythema multiforme/Stevens-Johnson/toxic epidermal necrosis?
Mortality 5-12% with SJS and >30% with TEN
Death often due to sepsis, electrolyte imbalance, multi-system organ failure
What is acute meningococcaemia?
Serious communicable infection transmitted via resp secretions; bacteria get into circulating blood
What is the cause of acute meningococcaemia?
Gram negative diplococcus N. meningitides
How does acute meningococcaemia present?
Features of meningitis -headache -fever -neck stiffness Septicaemia -hypotension -fever -myalgia Typical non-blanching purpuric rash on trunk and extremities (possibly preceeded by blanching maculopapular rash), can rapidly progress to ecchymoses, haemorrhagic bullae and tissue necrosis
How is acute meningococcaemia managed?
Abx e.g. benzylpenicillin
Prophylactic abx e.g. rifampicin, for close contacts (ideally within 14d)
What complications are associated with acute meningococcaemia?
Septicaemic shock
DIC
Multi-organ failure
Death
What is erythroderma?
Exfoliative dermatitis involving >90% skin surface
‘Red skin’
