EM and SCARs Dan Flashcards
what are triggers for eyrthema multiforme
No cause found in 50%
HSV most common, mycoplasma second
Other infections; many inc VZV, CMV and HIV, bacterial infections and histoplasmosis
Drusg; esp sulfa drugs and antiepileptics
topical drugs and chemicals
vaccinations
XRT
diseases inc malignancies eg. LE, PMLE, sarcoid, PAN, Carcinoma, lymphoma, leaukaemia
T/F
50% of cases of EM are EM minor
F
80% minor
20% major
what is difference between EM major and minor?
Minor;
No prodrome
skin limited only or mild mucosal involvement esp oral/genital
Major;
May be short prodrome of fever, rigors, malaise, arthralgia for 1-14 days
One or more mucosal sites significantly affected
Skin lesions widespread
Rarely can affect only mucosae
what is the onset and resoluton time for EM?
Eruption develops over 2-3 days resolves in 2-3 weeks
T/F
EM is photoaggravated
T
T/F
vesiculobullous EM is a type of EM Major
F
although som elsions may be bullous in EM major, vesiculobullous EM is an intermediate type
Red plaques with central bulla and marginal ring of vesicles; ‘herpes iris of Bateman’ . Usually in acral sites but only few lesions Looks like linear IgA disease
Mucous membranes often involved.
What is histo of EM?
Lichenoid reaction pattern
w/ true Interface dermatitis
Upper dermal perivascular lymphocytic infiltrate and dermal oedema
apoptotic keratinocytes can be high in epi
Sometimes spongiosis
May be epidermal necrosis but no large sheets
May be parakeratosis
What is management of EM?
Sun avoidance (sun can trigger HSV attacks) if recurrent try daily high SPF lip balm.
Symptomatic Rx only if mild.
Treat underlying condition if symptomatic – mycoplasma etc (does not improve the EM) or stop the causative drug.
Early ophth r/w if eyes involved
Oral lesions – topical steroid and anaesthetic agents, may need pain relief.
If severe consider steroids – pred at 0.5mg/kg reducing over 1-4 wks (debate about benefit).
If due to HSV, antivirals usually not useful even if started early but benefit if recurrent EM due to HSV
Recurrent cases – Azathioprine, thalidomide (also cyclosporine, dapsone, MMF but less evidence)
T/F
prophylactic antivirals can help recurent EM even if no viral cause found
T
what is erythroderma?
Red inflammation of 90% or more of BSA
exfoliative dermatitis means the smae thing but there is not always alot of exfoliation
causes of erythroderma?
Idiopathic (about 10%) Eczema (40%) – includes endogenous + other subtypes; - contact dermatitis – irritant or allergic - stasis dermatitis generalization - seb derm generalization Psoriasis (25%) PRP Sezary syndrome/erythrodermic MF (15%) blistering diseases esp pemphigus folleaceus Rare derm causes – HOSTING Lovely Ladies Double Ds; Hailey-Hailey Ofuji sarcoidosis Toxic shock syndrome Icthyoses Norwegian scabies GvHD Lupus Lichen planus Dermatophyte Dermatomyositis non derm causes Drugs (10%); Includes erythodermic DRESS or AGEP or exanthematous drug eruption Esp; mercury, arsenic gold and CASA; Carbamazepine/phenytoin Allopurinol Sulphasalazine Ampicillin/penicillin Hypereosinophilic syndrome Systemic Lymphomas or leukaemias HIV seroconversion
what are causes of erythroderma in a neonate?
Infection – SSSS, TSS, candidiasis, HSV, syphilis
Immunodeficiency – Omenn’s, SCID, Leiner’s
Ichthyoses – NBIE, BIE, Conradi HH, Netherton’s
Metabolic – Gaucher’s, biotin defcy
Drugs – ceftriaxone, vanc
Other – infantile seb derm, atopic derm, psoriasis, PRP, generalised mastocytosis
what are complications of erythroderma?
Hypothermia High output cardiac failure Fluid loss Hypoalbuminaemia - Reduced synthesis + protein loss due to chronic exfoliation Altered immune response
T/F
TCS should be avoided in erythoderma
F
mild TCS are fine unless cause is supected to be psoriasis then should avoid
Avoid irritants like tar, sal acid or UV
what is Papuloerythroderma of Ofuji?
Very pruritic rare type of papular erythroderma
over 50s esp men
brown-red, flat-topped papules on trunk and limbs
Spares face and flexures – deck chair sign
Can be koebnerising
Lesions become confluent
May be hyperkeratosis and fissuring of palms and soles, may be lymphadenopathy
Raosed eos and IgE - Remember eOfujE
Rx w/ emollients, antihistamines and topical or oral steroids
Reports of PUVA, AZA, CsA, etretinate
Persists for many years
o May remit spontaneously
T/F
AGEP onset is usually about 24 hrs after exposure to drug
T
few hrs – 48hrs
what is natural clinical Hx of AGEP?
Starts on face or in groin or axilla – confluent erythema with many small (38
20% get systemic features
After stoppingd rug skin starts to settle within a few days
Skin eruption lasts 1-2 wks and heals with superficial desquamation
illness settles in 15 days classically
Drug causes of AGEP?
Do My Pits Pus Today? Diltiazem Macrolides Penicillins/beta lactams Plaquenil Terbinafine and azole antifungals
What are major DDs for AGEP?
Infection - v important to r/o as pt has fever and neutrophilia
Acute pustular psoriasis (von Zumbusch type)
Exanthematous drug eruption - if pustules present usually will be follicular
SJS/TEN
Sweets
DRESS
Subcorneal IgA dermatosis/Sneddon Wilkinson
What does histo of AGEP look like?
Spongiosis Pustules in epi - most classically non-spongiform and subcorneal or intraepidermal papillary oedema perivasc infiltrate of neuts + some eos neutrophil exocytosis +/- eos exocytosis
What investigations should be performed in suspected AGEP?
Biopsy skin for H+E
swab pustules - should be sterile
FBC - neutrophilia typical, eosinophilia in 30%
ELFT - liver or renal impairment
CRP - may be inc esp if systemic organ involvement
Calcium - may be low
Blood cultures - do full septic screen as infection major DD
urine for MC+S and protein
CXR - effusions, septic screen
How is diagnosis of AGEP made?
Can use EuroSCAR group criteria - based on clinicla findings and histo;
Need 8 points;
typical appearing rash in typical distribution = 6
fever 38 or greater = 1
neutrophil count 7 x 10to the9/L or greater = 1
post pustular desquamation = 1
Typical histo = 3
can lose points if factors against the diagnosis or gain less points if non-typical findings
T/F
AGEP histo looks unusual if pt has psoriasis so hard to distinguish from pustular pso
F
AGEP histo usually the same regardless of whether pt has Hx of psoriasis
T/F
Pso pts with a pustular eruption are much more likely to have pustular pso than AGEP
F
people with Pso at higher risk of AGEP than others so don’t assume pustular psoriaisis just because pt has Pso
What is management of AGEP?
Stop drug – skin settles within a few days, illness settles in 15 days classically
Supportive cares
Condys baths
Dressings if required
Antibiotics only if superadded infection
Emollients to preserve skin barrier
Topical steroids for itch/inflammation – potent TCS can reduce time in hospital
No evidence for systemic steroids
Analgesia if required
Mortality
what 3 factors are important in the aetiology of DRESS?
Impaired metabolism of drug
reactivation of HHV6 and sometimes HHV7
specific HLA associations to rcns to certain drugs
