Clinical Reasoning: A young woman with progressive headache and pancytopenia

A 33-year-old woman was admitted to our hospital for treatment of pancytopenia and rash. Her history was notable for systemic lupus erythematosus as well as antiphospholipid antibody syndrome (APS) manifested by prior deep vein thrombosis, pulmonary embolism, and elevated anticardiolipin antibody (95 G phospholipids), β2 glycoprotein immunoglobulin G (IgG) (81 units/mL), and dilute Russell viper venom time (ratio 1.8). She was treated with enoxaparin 1 mg/kg twice daily for her APS. She also had a history of mild bilateral diffuse throbbing headaches occurring every couple of months beginning in her early 20s. Two weeks prior to admission, while vacationing in the Southeastern United States (without exposure to a forest), she developed chills, fatigue, and throbbing headache radiating to the right side of her face, accompanied by a whooshing sound in her right ear. Several days after headache onset, she presented to an outside hospital, where she reportedly had a normal head CT scan and brain MRI scan, but was noted to be pancytopenic (leukocyte count 0.5 × 103/μL, hemoglobin 7.7 mg/dL, and platelets 9 × 103/μL). She underwent a bone marrow biopsy, the results of which were unremarkable. She was discharged with a prednisone taper for suspected lupus flare. Her headache resolved but 2 days later she developed a new erythematous maculopapular rash involving the palms and soles for which she presented to our emergency room. Her complete blood count on admission was again notable for pancytopenia, with a leukocyte count 0.6 × 103/μL (absolute neutrophil count 900/μL), hemoglobin 8.0 mg/dL, and platelets 13 × 103/μL. Her enoxaparin was held given severe thrombocytopenia. The day after her admission, she developed a progressive return of similar quality right-sided headache again accompanied by a whooshing sound. Her headache was made worse by crying, coughing, and physical exertion. She denied any neurologic deficits and her vital signs were normal.