SymptomsBy Mayo Clinic Staff
Most people with viral encephalitis have either no symptoms or mild flu-like symptoms, such as the following:
- Aches in muscles or joints
- Fatigue or weakness
More-serious cases require prompt medical care. Additional signs and symptoms of more serious encephalitis may include the following:
- Confusion, agitation or hallucinations
- Loss of sensation or paralysis in certain areas of the face or body
- Muscle weakness
- Double vision
- Perception of foul smells, such as burned meat or rotten eggs
- Problems with speech or hearing
- Loss of consciousness
Signs and symptoms in infants and young children may also include:
- Bulging in the soft spots (fontanels) of the skull in infants
- Nausea and vomiting
- Body stiffness
- Inconsolable crying
- Poor feeding or not waking for a feeding
When to see a doctor
Get immediate care if you or someone you know is experiencing any of the symptoms associated with more-severe cases of encephalitis. Severe headache, fever and altered consciousness require urgent care.
Infants and young children with any signs or symptoms of encephalitis should receive urgent care.
May 15, 2014
- Longo DL, et al. Harrison's Online. 18th ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=4. Accessed Feb. 15, 2014.
- Encephalitis and meningitis fact sheet. National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/encephalitis_meningitis/detail_encephalitis_meningitis.htm. Accessed Feb. 17, 2014.
- Encephalitis. The Merck Manuals: The Merck Manual for Health Care Professionals. http://www.merckmanuals.com/professional/neurologic_disorders/brain_infections/encephalitis.html. Accessed Feb. 17, 2014.
- Hardarson HS. Acute viral encephalitis in children and adolescents: Clinical manifestations and diagnosis. http://www.uptodate.com/home. Accessed Feb. 15. 2014.
- Johnson RP, et al. Viral encephalitis in adults. http://www.uptodate.com/home. Accessed Feb. 15, 2014.
- Hardarson HS. Acute viral encephalitis in children and adolescents: Pathogenesis and etiology. http://www.uptodate.com/home. Accessed Feb. 15, 2014.
- Hardarson HS. Acute viral encephalitis in children and adolescents: Treatment and prevention. http://www.uptodate.com/home. Accessed Feb. 15, 2014.
- FAQ: Insect repellant use and safety. Centers for Disease Control and Prevention. http://www.cdc.gov/westnile/faq/repellent.html. Accessed Feb. 17, 2014.
- Insect repellent use and safety in children. U.S. Food and Drug Administration. http://www.fda.gov/Drugs/EmergencyPreparedness/ucm085277.htm. Accessed Feb. 17, 2014.
- Prevention & control. Centers for Disease Control and Prevention. http://www.cdc.gov/westnile/prevention/index.html. Accessed Feb. 17, 2014.