EMERGENCY DERMATOLOGY Flashcards
What is urticaria?
Local or generalised superficial swelling of the skin
Usually caused by allergy but non-allergy causes can be seen
Features of urticaria?
Pale pink, raised skin
Pruritus
Management of urticaria?
Non-sedating antihistamines
Prednisolone can be used for severe or resistant episodes
Drug causes of urticaria?
aspirin
penicillins
NSAIDs
opiates
What is angioedema?
Rapid swelling underneath the skin in the deep dermis and subcutaneous tissues
Usually caused by an allergy or retraction to a medication
What causes urticaria?
Inflamationlocal increase in permeability of capillaries and small venues
Histamine derived from skin mast cells are the major mediator
Where does angioedema typically affect?
The lips and tongue
What is erythema nodosum?
Inflammation of subcutaneous fat which causes tender, erythematous, nodular lesions
Usually occurs over shins but can occur elsewhere
Causes of erythema nodosum?
Infections - strep, TB, brucellosis
Systemic disease - sarcoidosis, IBD, Behçet’s
Malignancy/lymphoma
Drugs - penicillins, sulphonamides, COCP
Pregnancy
What is erythema multiforme?
A hypersensitivity reaction most commonly triggered by infections
Features of erythema multiforme?
Target lesions initially on back of hands/feet and then torso
Pruritus can occur
Causes of erythema multiforme?
Viruses - HSV, off
Idiopathic
Bacteria - mycoplasma, strep
Drugs - penicillins, sulphonamides, COCP, NSAIDs, allopurinol, carbamazepine, nevirapine
Connective tissue disease e.g. SLE
Sarcoidosis
Malignancy
What is erythema multiforme major?
A more severe version with 1 or more mucous membranes involved
Prognosis of erythema nodosum?
lesions continue to appear for 1-2 weeks and leave bruise-like discolouration as they resolve
They dont ulcerate and resolve without atrophy or scarring
What is stevens-Johnson syndrome?
A rare but serious skin reaction
Also known as toxic epidermal necrolysis
Cause systemic illness, circular rash, blisters and sores on lips/mouth/throat/eyes/urethra
Appearance of meningitis rash?
Rash usually starts as small red purpura before spreading quickly and turning into red/purple blotches
Non-blanching
What is erythroderma?
When >95% of the skin is involved in a rash of any kind
Causes of erythroderma?
Eczema
Psoriasis
Drugs e.g. gold
Lymphomas and leukaemias
Idiopathic
What is erythrodermic psoriasis?
Progression of chronic psoriasis to an exfoliating phase with plaques covering most of the body
Associated with mild systemic upset
Management of erythema multiforme and stevens-Johnson syndrome?
Early recognition and call for help
Full supportive care to maintain haemodynamic equilibrium
Complications of erythroderma?
Secondary infection
Fluid loss and electrolyte imbalance
Hypothermia
High-output cardiac failure
Capillary leak syndrome
Mortality 20-40%
Management of erythroderma?
Treat underlying cause where known
A->E
Assess fluid balance
Emolients and wet-wraps
Start on antibiotics if any signs of infection
Refer to derm
What is eczema herpeticum?
Severe primary infection of thr skin by herpes simplex virus 1 or 2
More commonly seen in children with atopic eczema
Features of eczema herpeticum?
Rapidly progressing painful rash
Monomorphic punched-out erosions 1-3mm in diameter
Systemically unwell with fever and malaise
Management of eczema herpeticum?
Admit children for IV aciclovir
What is necrotising fasciitis?
Medical emergency
A rapidly spreading infection of the deep fascia with secondary tissue necrosis
Causes of necrotising fasciitis?
Mixed anaerobes and aerobes (type 1)
Strep pyogenes aka group A strep (type 2)
Presentation of necrotising fasciitis?
Acute onset pain, swelling and erythema. Often presents with rapidly worsening cellulitis with pain out of keeping with physical features
Extremely tender over infected tissues with hypoaesthesia to light touch
Skin necrosis and gas gangrene are late signs
Systemically unwell - fever, tachycardia
What can be seen on XR in necrotising fasciitis?
Soft tissue gas
Average mortality rate for necrotising fasciitis?
20%
Management of necrotising fasciitis?
Urgent surgical referral debridement
IV antibiotics
Most commonly affected site for necrotising fasciitis?
Perineum
Known as fournier’s gangrene
