Cutaneous Loxoscelism Complicated by Tissue Necrosis: A Case Report and Surgical Resolution

Abstract

Introduction: Loxoscelism is a potentially lethal accidental envenomation mediated by the enzyme sphingomyelinase D, which can trigger manifestations ranging from local skin necrosis to massive intravascular hemolysis, coagulopathy, and multiple organ failure (cutaneous-visceral loxoscelism). In geriatric patients, the initial diagnosis represents a critical challenge because early systemic signs and wet epidermolysis can mimic severe drug-induced dermatosis like Lyell's syndrome, delaying specific therapy. Objective: To describe the clinical course, multisystemic paraclinical alterations, and the success of a stepped medical-surgical approach in a geriatric patient with severe cutaneous-visceral loxoscelism in Mexico. Case Presentation: A 67-year-old male patient presented to the emergency department in shock, with a 24-hour evolution after noticing a blister on the fifth finger of his left hand. Clinically, he developed progressive violaceous edema in the left upper extremity, blisters with necrotic changes, somnolence, dyspnea, chest pain, and oxygen desaturation down to 80% on room air. Baseline laboratories revealed metabolic acidosis, acute kidney injury (creatinine 1.9 mg/dL), massive microhematuria, and critical elevation of cardiac and molecular stress biomarkers (NT-proBNP 11,800 pg/mL, myoglobin 350 ng/mL, D-dimer 6,038 ng/mL), suggesting disseminated intravascular coagulation. After ruling out pulmonary embolism via computed tomography angiography, he was managed in the Intensive Care Unit, where antiloxosceles fabotherapy (Reclusmyn®) was administered alongside goal-directed fluid resuscitation, a dual antibiotic regimen (cefepime/clindamycin), and thromboprophylaxis. Within 72 hours, organ dysfunction resolved, and renal function normalized (creatinine 0.5 mg/dL), leaving defined areas of epidermolysis and dermonecrosis. On the 19th day of intrahospital stay, with stable laboratories, a surgical wash, debridement, and fasciotomy of the left hand with a tie-over graft placement were electively performed, achieving satisfactory healing and hospital discharge the following day. Conclusions: Systemic loxoscelism in the elderly requires high clinical suspicion to differentiate it from toxic-allergic dermatological syndromes. Timely initiation of specific fabotherapy and intensive support within the early therapeutic windows halt the progression of renal failure and vascular collapse, optimizing subsequent reconstructive outcomes.