Y5 - Erythema Multiforme Flashcards
def
an acute self-limiting but often relapsing mucocutaneous inflammatory condition
what is erythema multiforme associated with
hypersensitivity reaction associated with certain infections, vaccinations, medications
what is characteristic erythema multiforme
target lesions
what are target lesions
ring shaped lesion with an outer red ring and a central blistering area with normal skin tone
what are features of erythema multiforme
symptoms of mild URTI prior to episode
skin lesions are commonly around the mouth and any mucous membranes
epi
common in young adults
aetiology
a hypersensitivity response in susceptible individuals which can be induced by infection, vaccinations or medications
what infections are most commonly associated with EM
HSV
mycoplasma
also hep B, EBV, CMV
what medications are most commonly associated with EM
aminopenicillins
docetaxel (chemo)
TNFa-inhibitors
what vaccinations are most associated with EM
hep B vaccination
what is the difference between EM minor and major
EM minor has no mucosal involvement only cutaneous
EM major has involvement of 1 or more mucosal sites
risk factors
prior occurrence of EM
HSV
mycoplasma pneumonia
history
rapid onset of target lesions (3 zones, red rim, clearance zone, central blister) of extremities
recurrence
what is indicative of EM major
mucosal erosions (lips)
what are target lesions
3 zones, red rim, clearance zone, central blister
what are targetoid lesions
2 zones, red rim and central blister zone
where are target lesions most commonly found
extremities
where are targetoid lesions commonly found
trunk
what other findings are common with EM
if caused by mycoplasma pneumoniae
wheeze, crackles
investigations
1 bloods
-raised WCC
2 serology
-HSV 1 or 2 IgM
-cold -haemagglutination for mycoplasma pneumoniae
3 PCR
-HSV EM can be differentiated from HSV1 with positive varicella DNA
what % of the body should lesions in both EM minor and major cover
<10%
what sort of body painting is associated with EM
henna tattoos
what sort of hypersensitivity reactions are involved in EM
Type IV
what is the most important treatment for EM
symptomatic treatment (oral antihistamines, analgesics, local skincare)
