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Essentials of Diagnosis
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General Considerations
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Erythema multiforme
An acute inflammatory skin disease due to multiple causes
May also present as recurring oral ulceration and diagnosed by oral biopsy, with skin lesions present in only half of the cases
Was traditionally divided into minor and major types based on the clinical findings
Because ∼90% of erythema multiforme minor follow outbreaks of herpes simplex, the preferred term is "herpes-associated erythema multiforme"
The term "erythema multiforme major" has been abandoned
SJS/TEN is characterized by toxicity and involvement of two or more mucosal surfaces (often oral and conjunctival)
SJS/TEN is most often caused by oral or, rarely, topical medications, especially
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Classic target lesion, as in herpes-associated erythema multiforme, consists of three concentric zones of color change, predominantly on acral surfaces (hands, feet, elbows, and knees)
SJS/TEN presents with raised target-like lesions, with only two zones of color change and a central blister, or as nondescript reddish or purpuric macules
Pain may occur on eating, swallowing, or urination
Blisters are always worrisome and dictate the need for consultation
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Differential Diagnosis
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Skin biopsy is diagnostic
Direct immunofluorescence studies are negative
Blood tests are unhelpful
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Discontinue the offending medication
Open lesions should be managed like second degree burns
Move patients with > 25–30% BSA involvement to an appropriate acute care environment
Nutritional and fluid support and high vigilance for infection are important aspects of ...