A Triple Threat: Acute Systemic Lupus Erythematosus Unveiled with Hemophagocytic Lymphohistiocytosis and Toxic Epidermal Necrolysis.

A 36-year-old man with a history of arthritis, initially diagnosed as seronegative rheumatoid arthritis, developed new-onset SLE complicated by HLH and TEN. The patient presented with fevers, abdominal pain, vomiting, fatigue, rash, and significant weight loss. Despite multiple hospital visits and antibiotic treatments, his symptoms persisted. On admission, he exhibited extensive erythema, targetoid macules, full-thickness desquamation, and hemorrhagic crusting, covering about 30% of his body surface area. Laboratory findings revealed pancytopenia, positive ANA, anti-chromatin, dsDNA, hypocomplementemia, elevated ferritin, and hypertriglyceridemia. Skin biopsy showed interface dermatitis with full-thickness necrosis, and bone marrow biopsy confirmed hemophagocytic histiocytosis. The patient was diagnosed with SLE, HLH, and TEN and was treated with high-dose prednisone, IVIG, hydroxychloroquine, and mycophenolate mofetil, leading to significant improvement. This case highlights the complexity of diagnosing and managing concurrent SLE, HLH, and TEN. Early recognition and a multidisciplinary approach are crucial for effective treatment and improved outcomes. The patient's positive response to immunosuppressive therapy underscores the importance of addressing the underlying autoimmune condition in such complex presentations.