Stevens-Johnson Flashcards
Name the disease: Target like lesions with less than 10% of the body affected, commonly triggered by herpes simplex virus or mycoplasma
Erythema Multiforme
What differentiates SJS from eryhtoderma and eryhtematous drug eruptions?
SJS has mucosal involvment, while eryhtoderma and drug eruptions do not
What is phototoxic eruption?
Reaction to recent sun exposure, drug induced
What are two important things about SJS?
They have sever mucocutaneous reactions
-triggered by medications (usually 4-8 weeks after starting)
What determines SJS, vs. SJS/TEN, vs TEN?
Body surface affected.
less than 10% is SJS
10-30% is SJS/TEN
greater than 30% is TEN
What is prevalence of SJS to TEN?
SJS to TEN is 3:1, with 2-7 cases per million people per year
What is prevelance in HIV pts?
HIV patients are at 100 fold increase of SJS or TEN
What is mortalits for SJS and TEN?
SJS is 10%
TEN is 30%
What is most common etiology of SJS/TEN?
almost 75% is drug related
- happens 4-8 weeks after starting medication
- common in allopurinol (treament of gout), anti-seizure (phenobarbital and carbamazepine)
- antibacterial sulfonamides (like Bactrim)
- lamotrigine
- nevirapine
What are predisposing factors to SJS/TEN?
- HIV
- Genetics
- Underlying imunnologic disease
- medications
- infections like mycoplasma penumonia
What are the genetics in SJS/TEN and what is important about them?
HLA-B*1501 and HLA-B*5801
- must genetically test patients before starting anti-seizure medications
- also more common in asians.
What are some genetic polymorphisms with SJS/TEN?
CYP2C19- coding for cytochrome p450, leads to reduced clearence of medications in the liver and increased risk of severe cutaneous reactions
IL-4 Receptor gene
Prostaglandin E receptor 3 gene
-using 2+ durgs with the same metabolic pathway will increase risk of SJS/TEN
What is the underlying pathogenesis is SJS/TEN?
killing of keratinocyts by massive apoptosis, usually through CTLs, Fas-FasL, and NK cells
What is Granzyme B?
A cytolytic protein secreted by CTLs and NK cells
- induces apoptosis and a hihg level of ganzyme B is associated with disease
- perforin creates hole for entry.
- Granzyme B celaves Bid, recruits Bax and BAk, increases mitochondria permeability and release of cytochrome C
What is Granulysin?
Antimicrobial and cyottoxic chemical expressed by CTL and BK cells, causes the release of caspase 3 and keratinocyte death.
-found in blister fluid of lesions
Describe the histopathologic nature of thenecrosis found in SJS/TEN

Partial to full-thickness necrosis of the epidermis (keratinocytes)
What is the term used to descrive the symptoms 1-3 days prior to the onset of skin lesions?
Prodrome.
What is important about the cuatneous lesions of SJS/TEN?
They are tender to touch (painful), and start small and come togther with dark purple centers.
-start on face and torso and spread( spares the scalp, palsm, and soles)
What is important about the mucosal lesions and urogenital things in SJS/TEN?
Mucosal lesions: 90% of cases, painful curstin lesions
Urogenital: Urethritis (scarring) - leads to urinary retention in 65% of cases
What does this patient have?

Mucosal involvment with SJS/TEN, and infection
Can patients with SJS/TEN have ocular lesions?
YES 80% do.
0can lead to cornealulceration and panophthalmtitis
What will a CBC show in SJS/TEN?
It is not very helpful becuase it does not show the cause of the disease.
WIll see anemia, lymphoneia, neutropenia
What is the clinical course of SJS/TEN?
8 to 12 days
- fever
- severe mucous membrane involvment
- epidermal sloughing
What are complications of SJS/TEN?
Hypovolemic shock and renal failure
infection, DIC
-may lead to fatality
What is important about med hx relating to patient with SJS/TEN?
recent drug exposure or recent illness
- within the last 4 to 8 weeks
- recurrence of symptoms within 48 hours of restarting the offending medications (extremeley dangerous)
What would be the direct IF results of a SJS/TEN pt?
Negative becasue no ab production involved in disease
What test is used in diagnosis of SJS/TEN?
they will have positive nikolsky sign
-extension of the blister and or removal of epidermis in the rubbed area
How do you treat SJS/TEN?
High dose steroids (to slow down process)
IVIg (protect against infections and mediate immune system)
- cyclosporine (calcineurin inhibtor, stops NFAT)
- anti-TNF monoclonal antibody
- although all treatment remains controversial