How do symptoms of an encephalitis tick bite appear in a person? - briefly
The initial signs consist of fever, headache, and general malaise. Within several days, neurological manifestations such as confusion, neck stiffness, muscle weakness, or seizures may appear.
How do symptoms of an encephalitis tick bite appear in a person? - in detail
A tick bite that introduces an encephalitic virus initiates a clinical course that can be divided into three phases: incubation, systemic illness, and neurological involvement.
During the incubation period, which lasts from several days up to two weeks, the bite site may show a small, painless papule or erythema. Some patients notice a faint, expanding rash (often called an “eschar”) surrounding the attachment point, but many lesions remain inconspicuous.
The systemic phase appears shortly after incubation. Common manifestations include:
- High fever (≥38.5 °C) persisting for 2–5 days
- Severe headache, often described as throbbing
- Myalgia and generalized weakness
- Nausea, vomiting, and loss of appetite
- Mild photophobia or visual discomfort
These symptoms resemble those of other viral infections, making early recognition difficult without a history of recent tick exposure.
Neurological involvement marks the encephalitic stage. Signs may emerge abruptly or evolve over several days and typically involve the central nervous system:
- Altered mental status: confusion, disorientation, irritability, or lethargy
- Neck stiffness and positive meningeal signs
- Focal neurological deficits: weakness or paralysis of one limb, facial droop, or difficulty speaking
- Seizure activity, ranging from focal jerks to generalized convulsions
- Ataxia, gait instability, and loss of coordination
- Sensory disturbances: tingling, numbness, or abnormal sensations
In severe cases, patients develop coma, respiratory failure due to brainstem involvement, or autonomic instability (fluctuating blood pressure and heart rate). Laboratory evaluation often reveals lymphocytic pleocytosis in cerebrospinal fluid, elevated protein, and normal glucose. Neuroimaging may show diffuse cerebral edema or focal lesions depending on the viral strain.
Prompt medical evaluation is essential when any combination of fever, headache, and neurological signs follows a tick bite, especially if the bite occurred in regions endemic for tick‑borne encephalitis. Early antiviral therapy, supportive care, and monitoring for complications improve outcomes and reduce mortality.