Background <p>Systemic lupus erythematosus is an autoimmune inflammatory disease with extremely variable presentations. While a facial rash is the most common finding, other symptoms can include arthralgias, fatigue, and cytopenias. Abdominal symptoms are much less common presentations of lupus. Antiphospholipid syndrome is a related autoimmune disorder causing vascular thrombosis. Children with lupus frequently have antiphospholipid antibodies. We present a rare case of a 12-year-old female with a splenic infarction leading to a new diagnosis of lupus with associated antiphospholipid syndrome.</p> Case presentation <p>A previously healthy 12-year-old female presented with prolonged and recurrent fever, nausea, body aches and left sided abdominal pain. Her evaluation revealed anemia, thrombocytopenia, and proteinuria. A computed tomography of the abdomen showed a splenic infarction. While admitted to the hospital, she underwent extensive oncologic and rheumatologic testing. This evaluation resulted in a diagnosis of systemic lupus erythematosus. The patient’s hospital course was complicated by acute respiratory failure and myocarditis requiring intensive care unit transfer and care. Her symptoms and cytopenias gradually improved on oral steroids, hydroxychloroquine, and cyclophosphamide infusions.</p> Conclusions <p>Splenic infarction is less a distinct entity, but rather a symptom of an underlying disorder. Common etiologies include hypercoagulable states, infection, and oncologic and rheumatologic diseases. Patients with splenic infarctions are more likely to have longer hospital stays and higher mortality. This case is a reminder that a practitioner should consider hospitalization and further evaluation when splenic infarction is diagnosed, as this can be a signal of serious systemic disease.</p>