Anaplasmosis leading to neurological symptoms of trigeminal neuralgia

Anaplasmosis, formerly called human granulocytic anaplasmosis (HGA) is a co-infection from a tick that typically causes acute disease. In their article, "Trigeminal Neuralgia As the Principal Manifestation of Anaplasmosis: A Case Report," LeDonne and colleagues described human granulocytic anaplasmosis in an 80-year-old woman with neurological symptoms. [1]

According to the authors, the woman experienced a “sudden onset of severe, lancinating headache in the distribution of the fifth cranial nerve bilaterally.”¹ She had been treated for Lyme disease two months earlier following a tick bite and a rash on her torso. She had since been bitten by a non-engorged tick.

Her neurologic exam was felt to be consistent with a diagnosis of trigeminal neuralgia. Trigeminal neuralgia (TN) is a type of chronic pain that affects your face. It causes extreme, sudden burning or shock-like pain. It usually affects one side of the face.²

The patient’s mother had a history of trigeminal neuralgia. The doctors did not see any evidence of Lyme disease.

“However, anaplasmosis and ehrlichiosis can both develop over a shorter timeframe and without a noticeable rash, making these infections a more likely explanation of the patient’s signs and symptoms,” wrote the authors.

They added, “To confirm the suspected diagnosis, a tick-borne disease panel was ordered and was positive for Anaplasma phagocytophilum DNA by PCR.”

“Although severe headache is a common presenting symptom in patients with anaplasmosis, prior studies have not linked anaplasmosis and trigeminal neuralgia,” the authors explained.

“Our case suggests that anaplasmosis was the cause of our patient’s new-onset trigeminal neuralgia.”

The woman was treated with a 3-week course of doxycycline for Anaplasmosis and was prescribed gabapentin 300 for her trigeminal neuralgia.

She had marked improvement in her headaches. Her leukopenia, thrombocytopenia and abnormal hepatic enzymes returned to normal.

In their article, the authors reviewed the literature on Anaplasmosis, pointing out that the symptoms of Anaplasmosis are non-specific and may include fever, myalgia, and headache but no rash. In addition, patients may present with leukopenia, thrombocytopenia, elevated transaminases, and elevated lactate dehydrogenase.

“Rare cases of Anaplasmosis showcase post-infectious complications such as demyelinating polyneuropathy and brachial plexopathy,” wrote the authors. “However, this patient’s presentation of anaplasmosis with new onset trigeminal neuralgia appears to be unique and rare.”

The authors urge clinicians to consider Lyme disease, anaplasmosis, and Ehrlichia in “a patient presenting to the hospital with non-specific symptoms of fever, myalgia, and headache in tick endemic areas.”