A 10-year-old girl, suspected 2 days prior to have streptococcal pharyngitis, presented with diffuse erythema, tense bullae, Nikolsky-positive desquamation, as well as ulcerations of her oral and genital mucosa.She denied recent travel, sick contacts, or preceding and concurrent use of medications, including over-the-counter and herbal supple-
ments. A comprehensive viral polymerase chain reaction (PCR) panel,Mycoplasma pneumoniae PCR and IgM, streptococcal molecular antigen test, urine culture, blood culture, and rheumatologic serologies were negative. Based on the patient's clinical presentation and biopsy results, she was diagnosed with idiopathic toxic epidermal necrolysis.
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Pediatric Dermatology
BRIEF REFORTWith no clear trigger, she was diagnosed with idiopathic TEN. On day 10 of hospitalization, she was transferred to another hospital for escalation of care with 90% body surface area involvement and about 50% total desquamation. Happily, she fully recovered.
| D ISCUSS I ONThe incidence of idiopathic SJS and SJS/TEN overlap in the pediatric population is estimated to be 5%-16.6%. 4,5 Searching for both common and rare causes of SJS/TEN is critically important before identifying a case as idiopathic (Table 1). Often overlooked entities include food ingredients, insecticides, acetaminophen, and herbal remedies. 5 Additionally, infectious and autoimmune diseases must be ruled out.In our case, despite the thorough history and workup, an etiology was never found. This suggests that the pathophysiology of SJS/ TEN is highly complex and still poorly understood. A patient's predisposition to SJS/TEN is likely multifactorial and an interplay between genetics, the immune system, and environment. An underlying disease process or medication exposure needed to trigger the eruption may not be universal. Idiopathic SJS/TEN is therefore a particular challenge, as the clinical picture alone must guide the clinician toward the most appropriate management, one which optimizes the child's outcome and reduces mortality.
E N D N OTE* Comprehensive viral PCR panel: influenza A, influenza B, adenovirus, coronavirus, parainfluenza virus, respiratory syncytial virus A and B, chlamydia pneumonia, mycoplasma pneumonia, human metapneumovirus, human rhinovirus, enterovirus