How long after a tick bite do encephalitis symptoms appear in a person, and what signs are characteristic? - briefly
Encephalitic symptoms typically emerge 5 – 21 days after a tick bite, though onset can be as early as 2 days or delayed up to a month. Common signs include sudden fever, severe headache, neck stiffness, confusion, seizures, and focal neurological deficits such as weakness or altered consciousness.
How long after a tick bite do encephalitis symptoms appear in a person, and what signs are characteristic? - in detail
Tick‑borne encephalitis usually manifests after a short, asymptomatic phase that follows the bite. The incubation period ranges from 4 to 28 days, most often 7–14 days. In rare cases symptoms may appear as early as three days or as late as six weeks, depending on viral strain, inoculum size and host immunity.
The disease progresses in two stages. The first stage presents with nonspecific flu‑like complaints—fever, headache, muscle aches, fatigue—lasting 2–5 days and often resolves spontaneously. After a brief remission, the second stage develops, characterized by neurological involvement.
Typical neurological signs include:
- High fever persisting beyond the first stage
- Severe headache, often frontal or occipital
- Neck stiffness indicating meningeal irritation
- Photophobia and phonophobia
- Nausea, vomiting, and loss of appetite
- Altered consciousness ranging from drowsiness to coma
- Focal deficits such as limb weakness, ataxia, or tremor
- Cranial nerve palsies, especially facial nerve involvement
- Seizures, more common in severe cases
Laboratory findings support the clinical picture: elevated leukocyte count in cerebrospinal fluid, increased protein, and presence of TBE‑specific IgM antibodies. Early detection relies on recognizing the temporal link to a recent tick exposure and the biphasic pattern of illness. Prompt antiviral and supportive therapy improves outcomes, while delayed treatment increases the risk of permanent neurological sequelae.