Case Presentation: A 66 year old caucasian male with h/o RA- on chronic steroids, prostate CA s/p radiation and hormone therapy, admitted with acute onset of nausea, vomiting, rapidly progressive neurological deficits including slurred speech and inability to walk. He had received leuprolide injection followed by bicalutamide one week prior to presentation. Patient and his wife had traveled to Bahamas three weeks prior. They had a pet dog, who slept in the patient’s bed. Patient was noted to be febrile, hypotensive and tachycardic on arrival. Physical exam was positive for acute encephalopathy, expressive aphasia, redness of face and neck along with upper chest. Stroke workup including CTH, CTA H/N and MRI brain were negative. Lab work was consistent with hyponatremia, acute kidney injury, thrombocytopenia, elevated liver enzymes and lactic acidosis. He was initiated on treatment with broad spectrum antibiotics for presumed sepsis and stress dose steroids for suspected AI. He continued to decline clinically, developed worsening confusion and tremors, requiring ICU level of care. LP could not be pursued due to severe thrombocytopenia with PLT counts of 15. Extensive infectious workup was ordered including HIV, Hepatitis, EBV, CMV, Dengue, Chikungunya, Parvovirus and Ehrlichia serologies. He tested positive for Ehrlichia PCR. Ferritin was noted to be 19,907, IL-2 receptor was elevated to 25501.4, LDH and triglycerides were elevated, consistent with HLH secondary to tick-borne illness. He was diagnosed with Ehrlichiosis causing neurological compromise and was treated with doxycycline. Patient showed signs of clinical improvement with doxycycline and was eventually discharged home.
Discussion: Ehrlichia Chaffeensis is the etiologic agent of Human Monocytic Ehrlichiosis (HME). HME is endemic in southeastern, south-central and mid-Atlantic regions of United States. Most cases are seen in spring and summer months. The principal vector of E. Chaffeensis is the lone star tick (Amblyomma americanum). White-tail deer are the principal animal reservoir for E.Chaffeensis.Ehrlichiae are obligate intracellular bacteria that grow within membrane-bound vacuoles in human and animal leukocytes. HME typically presents as an acute illness; however, there is a wide spectrum of disease ranging from subclinical and self-limited to subacute and prolonged. HME infections are more likely to be severe and require hospitalization in adults. Ehrlichial diseases generally have an incubation period of one to two weeks, but a shorter period maybe seen. Majority of the patients have fever, myalgias, headaches, whereas neurological involvement with stroke like symptoms is not very common.HME caused severe illness with neurological compromise in this immunocompromised patient. Early diagnosis and treatment lead to significant improvement and decreased his risk of morbidity and mortality.
Conclusions: HME infections maybe particularly life-threatening in immunocompromised hosts. Severe illness like respiratory failure, GI hemorrhage and fungal superinfections can occur. HLH is also seen in solid organ transplant recipients. Early diagnosis and treatment is key to reduce significant morbidity and mortality in these patients. Obtaining a good history from the patient goes a long way.