Case Presentation: A 5 month old girl presented with 5 day history of fever and swelling of the right side of her neck.  Physical examination denoted a febrile, well appearing infant with a 3cm X 2.5cm indurated swelling posterior to midline of the mandible with erythema extending from chin to post-auricular area.  WBC count was 5.4 (47% neutrophils) with elevated inflammatory markers.  Neck ultrasound and CT showed extensive lymphadenopathy of the right cervical lymph nodes.  The child was started on IV Clindamycin but continued to be febrile.  Repeat laboratory studies showed rising CRP, normocytic anemia, and hemolysis.  Bedside incision and drainage returned pustular fluid.  Anti-microbial coverage was broadened to Piperacillin-Tazobactam and Vancomycin.  Blood and wound cultures were positive for MRSA (Vancomycin MIC of 1).  Antibiotics were changed to Daptomycin and Rifampin.  An echocardiogram was performed to evaluate for endocarditis.  No vegetations or valvular lesions were found, but a mass was seen suppressing flow of the superior vena cava.  Chest CT showed a heterogenous soft tissue density, and cardiac MRI revealed a clot with occlusion of the right internal jugular vein consistent with a septic thrombophlebitis.  The child was started on anti-coagulation therapy with Enoxaparin.  Fevers continued, and antibiotics were changed to Ceftaroline and Rifampin with resolution of the fever.  The child was discharged after factor anti-Xa levels reached the therapeutic goal and a PICC line for prolonged IV antibiotic therapy. 

Discussion: Fever and lymphadenopathy are commonly encountered by hospitalists; infectious causes account for many cases, but the differential spans hematologic, oncologic, rheumatologic, and anatomic entities.  Septic thrombophlebitis consists of thrombus formation due to inflammatory platelet aggregation in internal jugular and facial veins with possible emboli to the respiratory tract.  Although clots after infections are initially common, they experience a latency period due to antibiotic use.  Antibiotic resistance has led to a resurgence of septic clots with complications including endocarditis and acute respiratory distress syndrome.  The causative agent is usually Fusobacterium necrophorum.  Only eight cases (four pediatric) have been reported due to MRSA.  Anti-coagulation is controversial with some believing that anti-coagulation seeds the clot, heightening infection risk.  However, given the patient’s age and the risk for fatal sequelae, anti-coagulation with Enoxaparin was started.  This case posed many challenges including multiple radiographic studies to identify the suppressive mass and innovative antibiotic choices such as the new 5th generation cephalosporin Ceftaroline. 

Conclusions: Although lymphadenitis is a common diagnosis, uncommon conditions such as septic thrombophlebitis should be fully investigated.