Trigeminal Neuralgia Unmasked: A Case of Anaplasma Phagocytophilum Infection.

BACKGROUND: Anaplasma phagocytophilum is a bacteria transmitted to humans by tick bites, and like other tick-borne illnesses, its incidence has increased over the past several decades. A symptomatic patient infected with A. phagocytophilum typically presents with fever, chills, myalgia, other flu-like symptoms, leukopenia, thrombocytopenia, elevated liver enzymes, and inclusion bodies on a peripheral blood smear.

CASE REPORT: We report a case of a 72-year-old female with an infection of A. phagocytophilum who presented to the emergency department (ED) with intermittent pain that originated behind her right ear and radiated to their jaw and cheek. Laboratory testing revealed leukocytopenia, thrombocytopenia, elevated liver enzymes, inclusion bodies on blood smear, and a rash was identified on their left hip. The patient was treated with doxycycline for the infection and with dexamethasone and ketorolac for the trigeminal neuralgia. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: As the incidence of Human Granulocytic Anaplasmosis (HGA) increases, emergency physicians encounter more patients presenting to the ED. HGA can have life-threatening complications such as respiratory distress, shock, organ dysfunction and death. Emergency physicians must know how to diagnose and treat HGA to avoid complications, which can be difficult when unusual presentations are seen. Our patient did not have the common symptoms of fever, myalgia, and malaise. Instead, they presented with right ear and jaw pain, which was diagnosed as trigeminal neuralgia. The diagnosis of HGA in the ED relied on laboratory findings. These typical findings included inclusion bodies on a peripheral blood smear, leukopenia, thrombocytopenia and elevated liver enzymes. The patient's infection resolved with doxycycline (100 mg oral twice daily).