A Unique Presentation of Ehrlichiosis Causing Neutropenic Fever and Septic Shock with Developing Coagulopathy and Spontaneous Retroperitoneal Bleeding
Authors: Obianozie Promise , Fontanazza Gia , Conforti Anthony , Desai Balaji , Kwon Ashley 
Published: December 2024

Abstract: Ehrlichiosis is a tick-borne illness that typically presents with nonspecific symptoms of fever, malaise, headache, and myalgia. Lab abnormalities include thrombocytopenia, leukopenia, and elevated liver enzymes. Tick-borne diseases can cause a plethora of hematological dyscrasia. It is thus imperative that any Patient who comes in with hematological abnormality be screened for possible underlying parasitic infection.

Introduction: This case exposes a rare case of severe Ehrlichiosis in a 69-year-old female with risk factors for tick exposure. Her diagnosis of ehrlichiosis was delayed as no obvious tick bites was seen on physical examination. While her lab values were positive for UTI, despite appropriate antibiotics continues to be septic ultimately developing shock requiring vasopressor support. Her admission was complicated by spontaneous retroperitoneal bleeding and coagulopathy.

Case presentation: Patient is a 69-year-old with history of double valve replacement on Coumadin. She presented with complaint of malaise, fevers, mild suprapubic tenderness and was started on broad-spectrum antibiotic with Vancomycin and Cefepime with no improvement. she developed neutropenic fevers and shock and was transitioned to the ICU for vasopressor support. All of her cultures came back negative and extensive imaging was unremarkable. she continued to spike fevers with worsening neutropenia and leukopenia and was also in Afib with RVR necessitating the use of Neo-Synephrine for vasopressor. Upon further questioning the patient, she noted that she lives in the woods and was recently bitten by a tick. Her tick-borne panel eventually resulted with positive DNA for ehrlichiosis.

Treatment: Monotherapy with Doxycycline 100mg IV Q12h was initiated for 10 days course. Vancomycin and cefepime was discontinued. within 2 days of initiating doxycycline, her WBC and Liver enzymes improved to normal limits and her vasopressor was eventually weaned off. unfortunately, while patient improved clinically, her hemoglobin level dropped drastically to 5.9 necessitating transfusion with several PRBCS. She was noted to have large ecchymosis in her flank region measuring about 10cm. her INR was supratherapeutic at 7.1. Lab values was significant for pancytopenia, coagulopathy with worsening anemia. she required 8 units PRBC throughout hospitalizations. Reticulocytes, LDH, Haptoglobin and indirect bilirubin was consistent with hemolytic anemia. Given her ecchymosis and supratherapeutic INR, CT abdomen showed retroperitoneal bleeding lateral to the psoas muscles. unfortunately, she continued to have large ecchymoses in the chest wall and flank region and was transferred for urgent surgical intervention.

Discussion: Ehrlichiosis preferentially infects peripheral blood leukocytes as well as bone marrow causing suppression of all cell lines which we see in this patient. Her Reticulocyte index was suggestive of hypo proliferation. With elevated LDH, low haptoglobin, and elevated indirect bilirubin, there was a suspected component of autoimmune hemolytic anemia, however her direct antiglobulin test was negative. we obtained a peripheral blood smears which did not show any schistocytes making a diagnosis of Microangiopathy or macroangiopathic hemolytic anemia (MAHA) unlikely. The presence of ecchymosis, septic shock and coagulopathy makes diagnosis of DIC plausible. while She had abnormal coagulopathy, her fibrinogen levels were normal. While fibrinogen levels tend to be lower in DIC, it can be variable. A low or normal fibrinogen does not rule out DIC if other glaring clinical signs are present. Also, the absent of schistocytes does not rule out DIC. Her ISTH Score was 4, significant for Possible latent DIC. Ehrlichiosis invades monocytic and granulocyte cells causing a plethora of blood dyscrasias that we see in our patient. This organism can also trigger Pancytopenia associated with hypocellular bone marrow.

Conclusion: Doxycycline remains the standard treatment for ehrlichiosis, Early administration of doxycycline is crucial in patients with suspicion of tick-borne illnesses to avoid rapid severe progression and increase mortality. Patients with unexplained sepsis despite appropriate treatment, thrombocytopenia and transaminitis with residence in endemic areas, may benefit from empiric doxycycline coverage due to the consequences of delayed treatment of ehrlichiosis.