P3C206: Life Threatening Anemia and Acidosis Secondary to Systemic Loxoscelism in a Pediatric Patient

Introduction: Rashes are common in pediatric patients and most resolve without significant patient illness. In rare cases, they can represent life-threatening disease entities. History is crucial to determine a rash’s etiology, and barriers like developmental delay and language can complicate accurate diagnosis. We present a case of hemodynamic instability and hemolysis without known envenomation, which was diagnosed as systemic loxoscelism.

Case Description: A 10-year-old male with developmental delay presented with decreased activity and reduced oral intake for 4 days. An interpreter was used due to a language barrier. Initial vital signs were T 36.6°C, HR=120, RR=20, BP=117/66, and SpO2 96%. The child was listless with 1+ peripheral pulses and a capillary refill of 4 seconds. Skin exam showed a warm, hyperpigmented rash with rough texture on his trunk and upper extremities. Initial VBG showed a pH=7.04 and pCO2=27. His CBC showed hemolytic anemia with Hg=3.2g/dL and extreme leukocytosis with WBC=61x10*3/uL.

After initial fluid bolus the patient became hypotensive, and labs showed worsening acidosis with a pH=6.89, pCO2=22, and lactate of 27mmol/L. Resuscitative efforts included fluid boluses, antibiotics, blood transfusion, sodium bicarbonate, and high flow supplemental O2. He was subsequently admitted to the PICU. After initial stabilization, further history revealed the patient had a rash and cellulitis on his left shoulder and completed treatment with amoxicillin one week prior to presentation.

During his PICU course, multiple subspecialty services were consulted to assist with his workup. He received additional packed red blood cells (PRBC), rasburicase, steroids, and antibiotics. His rash evolved with desquamating areas and eschar formation at the left shoulder. Based on the extensive systemic symptoms, negative work-up for other etiologies, and an evolving eschar, the diagnosis of systemic loxoscelism was made. After 5 days, the patient recovered with supportive measures and is currently being followed for hemolytic anemia.

Discussion: Only 5 % of Brown recluse spider (Loxosceles reclusa) bites develop severe systemic manifestations. Life threatening toxicity can include severe hemolysis, acidosis, and autonomic instability. Treatments are largely supportive and include IV fluids, PRBC transfusions, and steroids. Antibiotics are often indicated if there are concerns for infection, and hemodialysis may be indicated for life threatening acidosis.

Often loxoscelism patients do not know they have a spider bite which can delay diagnosis. Some other challenges with the initial diagnosis and management of this case included language barrier and the patients developmental delay with decreased mentation.

Conclusion: Systemic loxoscelism is a rare and life-threatening condition that should be considered in patients with hemolysis and acidosis, especially in the setting of eschar formation. Diagnosing rare conditions in patients with language barriers and developmental delay can be challenging, and provider awareness can increase the chances of a proper diagnosis.