Microangiopathic hemolytic anemia with associated multiorgan failure is a medical emergency. The differential diagnosis for microangiopathic hemolytic anemia is broad and requires a systematic, focused approach at ruling out serious causes. However, with the rise of new vaccines and sporadic reports of vaccine-induced microangiopathic hemolytic anemia, it is essential for providers to include vaccines as a potential cause on their differential diagnosis. Here, we report the first case of respiratory syncytial virus vaccine-induced microangiopathic hemolytic anemia, anuric renal failure, and metabolic encephalopathy in the world.

Calcium oxalate nephropathy is a rare condition with both primary and secondary causes. Primary hyperoxaluria, an inherited disorder, leads to liver oxalate overproduction, whereas secondary hyperoxaluria, or enteric hyperoxaluria, may be multifactorial and typically occurs during adulthood, with etiologies including increased dietary intake of oxalate, destruction of the microbiota in the gastrointestinal tract that break down oxalate, and malabsorptive disorders that increase serum oxalate levels. Calcium oxalate crystal deposition can cause irreversible kidney injury necessitating kidney replacement therapy. Prompt recognition of the underlying etiology is necessary to minimize complications. Here, we present a case of calcium oxalate nephropathy of unclear initial etiology. Further consideration is given to alternative therapeutic options that address oxalate deposition-associated interstitial inflammation.

Primary angiitis of the central nervous system is an extremely rare diagnosis, with an incidence of 2.4 cases per 1,000,000 person-years. The exact cause of PACNS remains unknown, and typically cases present with a long prodrome. It is a diagnosis of exclusion, and various infectious, autoimmune, and malignant processes must be excluded prior to final diagnosis. Given the rarity of this condition, there is often a delay in diagnosis that can range from 6 to 23 months. It is imperative that all clinical providers be aware of this diagnosis when managing patients who present with insidious and non-specific neurological symptoms. We present a case of PACNS that responded well to a therapeutic regimen of high-dose steroids and cyclophosphamide.

Background: Spinal epidural abscesses (SEA) are rare, occurring 2.5–3 times per 10,000 hospital admissions. While streptococcus species comprise 7% of reported SEAs, Group A Streptococcus (GAS) has been described only once in the medical literature to our knowledge. Case presentation: We present a case of GAS pharyngitis with subsequent paraplegia from a GAS SEA. A 33-year-old female presented to the emergency department (ED) and was initially diagnosed with GAS pharyngitis and a suspected strained lower back. Following treatment with amoxicillin, she returned with worsened back pain, radiculopathy, and leukocytosis, for which she was treated with cyclobenzaprine. On her third presentation, she had new bilateral lower extremity weakness with decreased sensation, bilateral ankle clonus, and hyperreflexia. MRI of the thoracic and lumbar spine revealed a multiloculated SEA at T5-T10 requiring laminectomy and abscess evacuation. Intraoperative cultures grew Streptococcus pyogenes. Despite surgery, medical management, and physical therapy, she remained paraplegic. Conclusions: To our knowledge, this is the first report of SEA preceded by GAS pharyngitis. This case exposes the critical association between a recent infection, progression of back pain, eventual neurologic symptoms, and inflammatory markers that should trigger concern for SEA and early evaluation with MRI.

**Introduction/Hypothesis:** The incidence of anomalous right coronary artery (RCA) arising from the left coronary cusp is 0.92%.1,2,3 Patients a | POSTER