Severe drug reactions + emergency derm Flashcards
Criteria for AGEP
PHFAN
- pustules (sheets of non-folicular, sterile, superficial pustules)
- histo consistent
- fever > 38
- acute progression
- neutrophilia
Causative agents for AGEP
CCCAAAMPS (Camping with Fat MC)
- Ca Ch blockers
- Cipro
- Cephalosporins
- Antifungals
- Antimalarials
- Anticonvulsants
- Macrolides
- Penicillins
- Sulfonamides
Histology of AGEP
PuSSy DEn
- perivasc lymph/neuts
- subcorneal pustules
- spongiosis
- dermal oedema
- eosinophils
What percentage of patients with AGEP have systemic involvement?
18%
- hepatic, renal, pulmonary, BM (agranulocytosis_
What is the natural history of AGEP
Onset 2-5 days
Can be prodrome of burning/itch on skin
Onset in flexures - erythema, burning
Rapid progression to sheets of superficial pustules
+/- systemic involvement
Resolves over days-2 weeks after ceasing drug w superficial desquamation
Management of AGEP
Cease the drug Consider admission Monitor for/exclude infection Skin cares - condys soaks/ bleach baths TCS for itch/ irritation in the skin Rarely require PO prednisone (care that it isn't pustular PsO)
Ix in AGEP
confirm the diagnosis - 4mm PBx for histology
consider DIF to exclude other causes (IgA pemphigus)
Swab for m/c/s + viral swab HSV1/2 PCR
Septic Screen
FBC, ELFTs (can be systemic involvement)
ESR, CRP to help w monitoring
Causative agents for DRESS
Be Very Very MAAADS
- BRAFi
- Vancomycin (HLA 3201)
- valtrex
- Minocycline
- Azathioprine
- Allopurinol
- Anticonvulsants
- Dapsone
- Sulfonamides
Lag time for onset of DRESS
2-12 weeks
Pathophysiology of DRESS
T cell reaction (drug specific T cell reaction) HLA subtype susceptibility --- HLA3201 (vancomycin) --- HLA5802 (allopurinol) HHV6/7 reactivation
Diagnostic criteria for DRESS
RegiSCAR Abbrev
- AROS + LELO
- area > 50%
- rash c/w DRESS (maculopapular, exfoliative can be scattered pustules)
- organ involvement (see below)
- serology negative (ANA, Hep B/C, HIV, CMV, EBV)
ORGAN - LELO
- lymphadenopathy (2 or more basins)
- eosinophilia (scores from >0.7)
- atypical lymphocytosis
- organ - LFT > 2x ULN on 2 occasions)
Ix in DRESS
Confirm diagnosis + extent - 4mm PBx for histo, perilesional for DIF - FBC (eosinophilia) + film (atypical lymphocytosis) - ESR, CRP - ELFTs - coags - thyroid - TFTs - cardiac - ECG, Echo, TnI - pulmonary - CXR, RFTs, CT - GIT - FOB - pancreas - lipase - renal - urine m/c/s, Pr:Cr, blood pressure consider imaging - CT CAP, Abdominal US - HHV6/7 serology - LP if symptoms
Exc DDx
- septic screen
- Hep B, Hep C, HIV, EBV, CMV, syphilis
- ANA
Later
- consider patch test
- monitor for late complications up to 12-18 months
Management of DRESS
Cease the drug
Admit to hospital
Monitoring, obs, fluid regulation, electrolyte regulation, systemic complications
Commence PO Prednisolone (0.5-1mg/kg/day)
— consider IV methylprednisolone (500-1000mg/day for 3 consecutive days)
— aiming to weant over 2-3 months
— steroid sparing agent - IVIg, rituximab
General skin cares
TCS for symptomatic relief
Drug causes of erythroderma
CAAAN GOAL
- Ca ch blockers
- acitretin
- anllopurinol
- anticonvulsants
- NSAIDs
- Gold
- Omeprazole
- Ab’s
- Lithium
Aetiology of erythroderma
PsO, eczema (endogenous, irritant, allergic contact), drug, CTCL, PRP, Sarcoid, lupus, pemphigus foliaceous, hailey-hailey, darier’s, lichen planus….
Causative agents for SJS/TEN
SATTAAN
- sulfonamides
- allopurinol (HLA5801)
- terbinafine
- tetracyclines
- anticonvulsants (HLA1502)
- abacavir
- NSAIDs
Latency for onset of SJS/TEN
1-3 weeks