Lecture 10: Acute and Emergency Dermatology Flashcards
what is erythroderma?
- any inflammatory skin disease affecting > 90% of total skin surface
list some causes of erythroderma
- psoriasis
- eczema
- drugs
- cutaneous lymphoma
- hereditary disorders
- unknown
describe Stevens Johnson Syndrome (SJS) and toxic epidermal necrolysis (TEN)
- skin conditions caused by a severe reaction to a drug
- secondary to drugs such as: antibiotics, anticonvulsants, allopurinol, NSAIDs
- can be delayed onset
Stevens Johnson Syndrome (SJS) clinical features
- 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
Toxic Epidermal Necrolysis (TEN) clinical features
- often presents with prodromal febrile illness
- ulceration of mucous membranes
rash:
- may starts as macular, purpuric or blistering
- rapidly becomes confluent
- sloughing off large areas of epidermis: desquamation > 30% BSA
- Nikolsky’s sign may be positive
SJS and TEN management
- identify and stop culprit drug ASAP
- supportive therapy
- ? high dose steroids
- ? IV immunoglobulins
- ? anti-TNF therapy
- ? ciclosporin
what scoring system is used to predict mortality rate in SJS or TEN?
SCORTEN
what are the long-term complications of SJS/TEN?
- pigmentary skin changes
- scarring
- eye disease and blindness
- nail and hair loss
- joint contractures
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
- self-limiting
clinical features of drug reaction with eosinophils and systemic symptoms (DRESS)
- onset 2-8 weeks after drug exposure
- fever and widespread rash
- eosinophilia and deranged liver function
- lymphadenopathy
- +/- other organ involvement
DRESS treatment
- stop causative drugs
- symptomatic and supportive
- systemic steroids
- +/- immunosuppression or immunoglobulins
pemphigus clinical features
- antibodies targetted at desmosomes
- skin- flaccid blisters, rupture very easily
- intact blisters may not be seen
- common sites: face, axillae, groin
- Nikolsky’s sign may be +ve
pemphigoid clinical features
- antibodies directed at dermo-epidermal junction
- intact epidermis forms roof of blister
- blisters are usually tense and intact
what are common causes of erythrodermic psoriasis and pustular psoriasis?
common causes:
- infection
- sudden withdrawal of oral steroids or potent topical steroids
erythrodermic psoriasis and pustular psoriasis treatment
- exclude underlying infection
- bland emollient
- avoid steroids
- often require initiation of systemic therapy
urticaria clinical presentation
- weal, wheal or hive
- angioedema: deeper swelling of the skin or mucous membranes
causes of chronic urticaria (> 6 week history)
- autoimmune/idiopathic (60%)
- physical (35%)
- vasculitic (5%)
- rarely a type 1 hypersensitivity reaction
