D104-11 Fatal Linear IgA Bullous Dermatosis Masquerading as Steven-Johnson Syndrome

Introduction Linear IgA bullous dermatosis (LABD) is a rare autoimmune disorder with generally good prognosis. Here we present for the first time, a case of drug induced LABD, initially thought to be Steven Johnson Syndrome (SJS), which eventually led to necrotizing pneumonia and a fatal outcome. Case A 66-year-old lady with chronic diarrhea due to lymphocytic colitis presented for tachycardia and hypovolemia. She received one dose of ciprofloxacin and metronidazole and was resuscitated with intravenous fluids. The next day, a diffuse petechial rash appeared which developed into bullous lesions within 24 hours. The patient was presumed to have SJS. A skin biopsy was performed, and etanercept was initiated. The biopsy was consistent with LABD, showing inflammatory subepidermal blister with neutrophils, lymphocytes and occasional eosinophils and necrotic keratinocytes with strong linear deposition of IgA present along the basement membrane zone on immunofluorescence, and the patient was started on dapsone and a prednisone taper. During this time, the patient developed new oral and cutaneous lesions due to herpes reactivation [positive for HSV-1 DNA in nasopharynx and in skin lesions]. Her clinical condition worsened secondary to right lower lobe MRSA pneumonia per pulmonary infiltrates and bacteremia. After an initial course of cefepime and linezolid for sepsis and high dose acyclovir for diffuse cutaneous herpes, the antibiotics were narrowed to ceftaroline. Oxygenation initially improved but the patient was persistently bacteremic. Repeat imaging showed cavitary lesions in the right lower lobe. The patient’s condition progressed to shock, ARDS, and was complicated by pneumothorax and acute renal failure. Despite multiple life support treatments, she did not show clinical improvement, and the family transitioned to comfort-oriented care. Discussion LABD is a rare condition affecting 0.2-2.3 cases/million individuals/year, among which fatal complications have rarely been reported. Our patient likely developed LABD due to ciprofloxacin exposure, which is an uncommon association. Her mucosal disruptions likely led to bacterial translocation, and necrotizing pneumonia. Due to her weakened immune status from both LABD and etanercept and prednisone, despite aggressive therapies, she remained persistently bacteremic, which lead to multiorgan failure and to her demise. Our case highlights the importance of prompt evaluation of blistering dermatoses for accurate treatment, and appropriate wound care to prevent infections which can lead to severe complications.