Background: Fever, headache and confusion are considered as the cardinal symptoms of encephalitis. The symptoms of encephalitis can mimic as rhinitis, familiarity with the clinical spectrum and features is important for clinicians to optimize clinical management. Case Report: A 30-year-old female patient presented with sinus area tenderness, but otherwise, she appeared healthy and conscious. She was thought of having rhinitis, due to her past history of having colds. However, application of ephedrine into the nasal cavity aggravated her headache. Headache improved significantly following anti-viral treatment and reduction of intracranial pressure. However, ethmoid area tenderness persisted, which was relieved by using tetracaine spraying into the nasal cavity. Conclusion: Considering her headache started at the canthal area, the organism might reach intra-cranial through anterior ethmoidal nerve. The anterior ethmoidal neuralgia might be a post-encephalitis sequel like post-encephalitis epilepsy.