Key Takeaway

Exposure to a bat without a visible bite wound, nonspecific symptoms, and an initial misdiagnosis: What begins as what appears to be a herpes infection develops into fulminant encephalitis within a few days. The case published in the CMAJ of an 11-year-old boy from Canada illustrates how deceptive the course of rabies can be — and why any direct contact with a bat must be medically evaluated.

The Patient and His Medical History

The patient is 11 years old, immunocompetent, and had been healthy. When his parents brought him to the emergency department of a municipal hospital in Ontario, Canada, he complained of painful difficulty swallowing and vomiting. The boy had no known allergies and no tick bites and had not traveled abroad. There were no known infected contacts.

The symptoms began about a week earlier: Initially, the boy felt tingling and numbness on the right side of his face. The symptoms worsened; he lost his appetite and later developed swelling on the right side of his face. Four days after the onset of symptoms, the family visited an emergency department for the first time. There, doctors suspected Bell palsy, likely associated with a herpes simplex infection. The boy was prescribed valacyclovir, 1 g three times a day. However, due to severe pain when swallowing, he was barely able to take the medication.