Derm emergencies

Question 1

STEVENS JOHNSON/TOXIC EPIDERMAL NECROLYIS
i) what are they? what happens? what is the result on the skin?
ii) which occurs when less than 10% body SA is affected? which is when it is more than 10%?
iii) name three causative medications? name three causative infections?
iv) how does presentation usually start? (4) then what develops? what happens to the skin after a few days?
v) what can happen to lips and mucus membranes? what can happen to eyes?

Answer 1

i) spectrum of the same pathology
disproportionate immune response causes epidermal necrosis > blistering and shedding of top layer of skin
ii) SJS in <10% and TEN in >10%
iii) meds - anti epileptics, antibiotics, allopurinol, NSAIDs
infections - herpes simplex, mycoplas pneum, CMV, HIV
iv) usually starts with non spec symptoms eg fever, cough, sore throat, sore mouth, eyes and itchy skin
then develop a purple or red rash that spreads across skin and starts to blister
then skin breaks away and leaves raw tissue underneath
v) lips/muc mems can also have pain erythema blistering and shedding
eyes = inflamed and ulcerated

Question 2

SJS/TEN MX
i) what should happen immediately?
ii) name three things that are essential
iii) name three treatment options
iv) name three complications

Answer 2

i) medical emergencies > admit to derm or burns unit for treatment
ii) supportive care - nutritional care, antiseptics, analgesiam opthalmology input
iii) steroids, immunoglobulins and immunosupressants
iv) secondary infection, permanent skin damage and visual complications (severe scarring and blindness)

Question 3

ERYTHEMA MULTIFORME
i) what is it? what type of reaction is it? what two things is it most commonly caused by? which virus can it be assoc with? which type of pneumonia?
ii) how does it present? what are the characteristic lesions? does it usually affect the mucus membranes?
iii) how quickly do symptoms come on? name three other assoc symptoms that may be seen
iv) how is dx made?

Answer 3

i) erythematous rash caused by a hypersensitivity reaction
common caused by viral infections and medication
also assoc with herpes simplex and mycoplas pneumonia
ii) presents with a widespread utchy rash - charac target lesions (red rings within larger red rings - dark red at centre like bulls eye)
doesnt usually aff mucus mem but causes a sore mouth
iii) symptoms come on abruptly over a few days - can be assoc with mild fever, stomatitis, myalgia, headache, flu like symptoms
iv) dx clinically based on appearance of the rash

Question 4

EM MX
i) how can a clear underlying cause be tx? what should be done if there is no clear underlying cause?
ii) how quickly does it normally resolve? which type of cases may be recurrent?
iii) which area may be affected in severe cases? what needs to happen?
iv) name three treatments that can be used in severe cases

Answer 4

i) clear cause - supportive ,x
no clear cause - do CXR to look for mycoplas pneum
ii) normally resolves in 1 -4 weeks spontaneously
may be recurrent if assoc with cold sores
iii) severe can affect the oral mucosa - need admission
iv) tx with IV fluid, analgesia and steroids (abx when infection is present)

Question 5

ERYTHRODERMA
i) what is it? what is it known as when there is associated exfoliation
ii) name four causes
iii) what type of rash is seen? name three symptoms? after how many days may scaling start?

Answer 5

i) term used when more than 95% of the skin is involved in a rash of any kind
exfoliation = exfoliative dermatitis
ii) can be generalised spread of a primary skin disorder or idiopathic
can be caused by eczema, psoriasis, drugs (gold), lymphoma, leukaemia
iii) measles like eruption, dermatitis or plaque psoriasis
skin feels warm, itch, eyelid swelling, scaling 2-6 days later

Question 6

NON BLANCHING RASHES
i) what are they caused by? what are petichiae? what are purpura?
ii) name five differentials
iii) what mx should always be done for a patient with a non blanching rash

Answer 6

i) caused by bleeding under the skin
petichiae - small <3mm non blanchign red spots caused by burst capillaries
purpura - larger >3mm non blanching red purple macules or papules due to leaky bv
ii) meningococcal sepsis/other bacterial sepsis, henoch schonlein purpura (purpuric rash on leg/buttocks), acute leuakemia, mech, traumatic, viral illness eg influenza an enterovirus
iii) always urgent refer