SJS/ TEN Flashcards
pathomechanism is
widespread apoptosis o keratinocytes induced by a cell-mediated cytotoxic
reaction.
histo
Full-thickness necrosis o the epidermis and a sparse lymphocytic in ltrate
%epidermal detachment
SJS: < 10% epidermal detachment. SJS/TEN overlap: 10 to 30% epidermal
detachment.
TEN: > 30% epidermal detachment.
age sex
AGEOFONSET Anyage,butmostcommonin adults > 40 years. Equal sex incidence. OVERALLINCIDENCE TEN: 0.4 to 1.2 per million person-years. SJS: 1.2 to 6 per million person- years.
RISKFACTORS Systemiclupuserythematosus, HLA-B12, HLA-B1502, and HLA-B5801 in Han Chinese, and HIV/AIDS
t ime rom rst drug exposure to onset o symptoms
1 to 3 weeks. Occurs more rapidly with rechallenge
manif
Prodromes:
ever, malaise, arthralgias 1 to 3 days prior to eruption. Mild to moderate skin tenderness, conjunctival burning or itching, then skin pain, burning sensation, tenderness, paresthesia. Mouth lesions are pain ul, tender. Impaired alimentation, photophobia, pain ul micturi- tion, and anxiety.
SKIN LESIONS Prodromal Rash. Morbilli orm, can be target-like lesion, with/without purpura (Fig.8-7);rapidcon uenceo individual lesions (Fig. 8-8); alternatively, it can start with di useerythemaandnorash(Fig.8-9).
Early. Necrotic epidermis rst appears as macu- lar areas with a crinkled sur ace that enlarge and coalesce(Fig.8-7).Sheetlikelosso epidermis (Fig. 8-8). Raised accid blisters that spread with lateral pressure (Nikolsky sign) on erythematous areas.Full-thicknessepidermaldetachment yieldsexposed,red,oozingdermis(Fig.8-9) resemblingasecond-degreethermalburn. Distribution. Initialerythemaon ace, extremities,becomingcon uentovera ew hours or days. Epidermal sloughing may be generalized, resulting in large denuded areas (Figs. 8-8 and 8-9). T e scalp, palms, and soles may be less severely involved.
when does regrowth of elidermis occur and complete
Regrowth o epidermis begins within days; completed in > 3 weeks
% of those who have conjunctival lesions
EYES 85%haveconjunctivallesions
general shstemic findings
Fever usually higher in EN than in SJS.
■ Usually mentally alert. Distress caused by
severe pain.
■ Cardiovascular: Pulse may be > 120 beats/min.
Blood pressure.
■ Renal: ubular necrosis may occur. Acute
renal ailure.
■ Respiratory and GI tracts: Sloughing o
epithelium with erosions
hema findings
Anemia, lymphopenia; eosino- philia uncommon. Neutropenia correlates with poor prognosis. Serum urea increased, serum bicarbonate decreased
hema findings correlates with poor prognosis
neutropenia
DP
DERMATOPATHOLOGY Early. Vacuolization/ necrosiso basalkeratinocytesandthroughout the epidermis.
Late findings
Late. Full-thicknessepidermalnecrosisand detachment with subepidermal split above basement membrane. Sparse lymphocytic
in ltrateindermis.Immuno uorescencestud- ies unremarkable, ruling out other blistering disorders
a prognostic scoring for pxs w epidermal necrolysis
scorten
tx
■ Early diagnosis and withdrawal o suspected drug(s).
■ Patients are best cared or in an intermediate or intensive care unit
Manage replacement o IV uids and electrolytes as or patient with extensive thermal burn. However, less uid is usually required as or thermal burn o similar extent.
■ Systemic glucocorticoids early in the disease and in high doses are reported help ul in reducing morbidity or mortality (as is also theexperienceo theauthors),butthishas been questioned. Late in the disease, they are contraindicated.
■ High-dose IV immunoglobulins halt progression o EN i administered early. T isisquestionedbysomeauthors;the discrepancy may be explained by the
di erentproductsandbatchesused.
■ With oropharyngeal involvement, suction to prevent aspiration pneumonitis.
■ Surgical debridement is not recommended. ■ Diagnose and treat complicating in ections, including sepsis ( ever, hypotension, and
change in mental status).
■ reat eye lesions early with erythromycin
ointment.
