Case Presentation: 46 yo African American woman with MCTD on plaquenil and prednisone with ILD, PAH, chronic pseudoobstruction, gastroparesis and chronic malnutrition requiring TPN who originally presented at her local hospital with intractable nausea, vomiting and abdominal pain.  She had recently presented numerous times for these complaints and therefore was transferred to a different facility.  Upon arrival she was noted to have fever (38.6C), HR 122 and BP 86/52.  Physical exam was unremarkable with normal appearing RUE PICC line and venting PEG tube and blood work was unrevealing.  She was diagnosed with a likely central line infection. Her PICC line was removed and she was started on Vancomycin and Zosyn. Due to persistent high grade fevers and negative initial blood and PICC cultures, evaluation for fungal infection was undertaken and micafungin was empirically started. She developed anemia (Hb 9.0 -> 6.8) and thrombocytopenia (plts 189 -> 92). There was a concern for possible GI bleed as she was noted to have bloody output from her venting PEG tube. Anemia work-up included ferritin, which resulted at 86290 ng/mL. A reassessment of her clinical situation at this time raised the concern for HLH.  Further work-up included triglycerides 426 mg/dL, fibrinogen 320 mg/dL, and CT scan that showed no evidence for hepato-splenomegally. A bone marrow biopsy demonstrated rare hemophagocytosis and EBV PCR returned weakly positive (<1000 copies). Her H score was calculated as 253, therefore she was diagnosed with HLH and started on iv dexamethasone and rituximab. Her fevers resolved, ferritin improved to 11,000ng/mL and blood counts improved with treatment. She was discharged on maintenance dexamethasone.

Discussion:

Fever is a common presentation encountered in hospital medicine. Clinicians must allow additional clinical signs to show the direction for further work up. For this patient, the additional signs initially pointed to a likely infectious source. However, as her course progressed this had to be re-assessed and the differential broadened.  Hospitalists must be aware of anchoring bias and be willing to question original diagnoses and assumptions when additional clinical information reveals itself.

HLH is a rare immune system disorder which is aggressive and can be life threatening prompting the need for timely diagnosis and treatment. While HLH is associated with rheumatologic diseases, only 1 case has been previously reported to be associated with MCTD, and only pediatric cases have been reported with TPN. The H score was recently developed to aid in the diagnosis of this complex syndrome, and hospitalists should be aware of its utility.

Conclusions: : HLH is an uncommon disease but rare cases have been reported in patients with TPN and MCTD making this case unique. Even though it is common to have infectious causes for fever in hospital medicine, keeping broad differential is important to avoid anchoring bias. Lastly H score can be an important tool to assist in diagnosing HLH.