Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Flashcards
How does Stevens-Johnson syndrome present typically?
Flu-like symptoms, painful pustules or blisters in the mouth, fever, ocular lesions.
Blisters are very painful to the touch
Where do lesions in Stevens-Johnson syndrome typically present?
Starts on the face and torso then spreads.
Where does Stevens-Johnson typically spare?
Does not affect the scalp, palms, soles
A 14-year-old boy presents to the emergency department with a 1-day history of fever associated with lip swelling and peeling. Within 48 hours he developed involvement of his ocular and urethral mucosa along with an erythematous papular rash on his trunk that spread to his extremities. target lesions can be seen on the back. He was diagnosed with Stevens-Johnson syndrome and admitted to the hospital.
What is a hallmark of Stevens-Johnson in this case?
- Distribution is wide-spread
- Oral cavities and conjunctiva is involved
- start local blisters and start to spread
- Nikolsky positive
What drugs are common in precipitating Stevens-Johnson?
- ) Allopurinol
- ) Anti-seizure medications (phenytoin and carbamazepine)
- ) Bactrim (Trimethoprim-Sulfamethoxazole)
- ) Lamotrigine
- ) Nevirapine
- ) Oxicam NSAIDs
What are some infectious agents that could precipitate SJS
-Mycobacterium tuberculosis
-CMV/EBV
-group A streptococci,
-hepatitis B
Epstein Barr virus,
-Histoplasma, Coccidioides
-Diphtheria
What are some genetic factors predisposing one to SJS?
HLA-B*1502 (Asians at a higher risk for having this)
-carbamazepine, phenytoin, phenobarbital
HLA-B*5801
-Allopurinol
CYP2C19 p450: reduced clearance of meds in the liver
IL-4 PMPs
Prostaglandin E receptor 3 Gene PMPs
How are keratinocytes destroyed in SJS/TEN?
Medications can bind to MHC class I and to TCR T cell receptors–>clonal expansion of CTLs–>Fas-Faslingand interactions between CTLs and Keratinocytes which activates caspases within Keratinocytes inducing apoptosis
Death mediators: Granzyme B (T cells and NK/T Cells—more B worse prognosis) and Granulysin (CTLs and NK cells)
Acute complications of SJS
Sepsis, massive volume loss from epithelia loss, infection: staph aureas, pseudomonas, electrolyte imbalance
Long term complications of SJS?
Change in pigment color (postinflammatory hyperpigmentation)
Scarring: vulvovaginal or urethral stenosis (predispose for renal issues because of difficulties urinating)
Loss of nails
Chronic Bronchitis
Serious Ocular problems Blindness Dry/watery eyes Photophobia Adhesion of the skin to the eyeball
what is the differential diagnosis for someone with SJS?
- ) Erythema Multiforme triggered by HSV of mycoplasma
- ) Erythroderma and erythematous drug eruptions (lack mucosal involvement)
- )Acute generalized exanthematous pustulosis (beta lactam antibiotics, pustules present)
- ) Phototoxic eruptions (e.g.: sun exposure while on antibiotics)
- )Staphylococcal scalded skin syndrome (no mucosal involvement)
- ) Paraneoplastic pemphigus
- ) Linear IgA bullous dermatosis (IgA deposition, rare)
- )Stevens-Johnson/Toxic Epidermal Necrolysis
What predisposing factor increasing the risk of developing SJS by 100 fold?
HIV
Is a biopsy necessary to confirm dx?
No, but a punch biopsy can be helpful to rule out bullous diseases, immunohistochemistry can help with this too to ensure it is not an autoimmune-related condition
What is the treatment for SJS?
High does steroids (to decrease inflammatory cytokines and slow down the process)
IVIg to help mediate the immune system
Also treat the infections: antibiotics, skin and eye care, pain mgmt, ICU burn unti
What is the mortality of SJS compared to TEN?
10% vs 30% and these are dependent on how far along the condition is and the surface area of body affected.
