November 14, 2011 by dailybolusoflr
Toxic Epidermal Necrolysis and Stevens-Johnson Syndrome (TEN vs. SJS)
· Two diseases of varied severity, thought to be on a continuum of a disease that affects the skin and mucous membranes.
· Both are immune complex mediated hypersensitivity processes.
· In both cases, fluids and infectious precautions are indicated whereas steroid use if controversial due to the risk for infection
· Most cases are triggered by either preceding medication or by a URI
· Typically presents with fever and influenza like symptoms (myalgias, malaise) and can occur 1-3 weeks after inciting event
· The rash is similar to erythema multiforme (and in fact TEN is considered the most severe form of EM) with large macules or atypical target lesions that coalesce into large bullous lesions that denude and slough within 24 hours. It is > 30% of the BSA.
· Sloughing occurs in all layers of the epidermis and accounts for the high mortality rate of 30-50% (think risks similar to burn patients)
· Mucous membranes are involved and often are seen as erosive oral lesions but can present with intestinal or vaginal involvement, as well as corneal involvement
· Epithelial necrosis of the bronchial epithelium can lead to pulmonary edema and respiratory failure
· Nikolsky sign is positive
· Hair is intact
· Most cases are triggered by a preceding medication and much less commonly an infectious process
· Typically present with fever and influenza like symptoms (myalgias, malaise) and can occur 1-3 weeks after inciting event
· The rash is similar to erythema multiforme (SJS is considered an intermediate disease process on the EM spectrum) with macules or atypical target lesions that develop into blisters with or without sloughing. It involves detachment of < 10% of the BSA, although “overlap” diagnoses of TEN/SJS exist with blistering/sloughing affecting between 10-30% of BSA.
· Involvement of at least 2 mucous membranes is typically found with oral and ocular involvement being more highly found
· Mortality is much lower (1-3%) and prognosis is excellent
· Nikolsy sign can be positive, but this typically represents a more severe form of the disease, which is more likely to pass into the “spectrum of TEN”
· Hair is intact
Ref: Crit Care Med 2011 Vol. 39, No. 6 and Current Allergy and Asthma Reports 2007, 7:243–247