A 17–year–old Caucasian female presented to our hospital with complaints of severe, throbbing, fronto–temporal headache for 5 days; associated with photophobia, nausea and non projectile vomiting. There was an isolated episode of 102°F fever two days prior, without any chills or rash. There was no history of seizures or altered mental status. There was no personal or family history of migraine. On examination she was awake, alert and fully oriented and vital signs were stable. Neurological exam including higher mental functions, cranial nerves, motor and sensory systems, coordination and gait was normal. There was marked photophobia but pupillary size and reflexes, external ocular movements, visual fields and fundoscopy were normal. Presence of neck rigidity was questionable but Kernig’s sign was absent. Examination of the skin, lymph nodes, oropharynx, cardiorespiratory system and abdomen was benign. A non–contrast computerized tomographic scan of the brain was unremarkable. Complete blood count and basic metabolic profile were normal. A diagnosis of Status Migrainosus was made and dexamethasone and promethazine were administered. However, the symptoms persisted, so a lumbar puncture was performed. Cerebrospinal fluid was clear, with opening pressure of 300 mm of water, nucleated cell count of 580 cells with 94%lymphocytes, glucose of 42 mg/dl (blood glucose 107 mg/dl) and proteins of 157 mg/dl. Headache and nausea were significantly relieved by the procedure and intravenous acyclovir was started empirically. CSF studies for Cryptococcal antigen, India Ink preparation, VDRL, FTA, Herpes Simplex PCR, Gram Stain and cultures were negative. On the third day, a painless, fine, red, maculo–papular rash appeared over the right C7 dermatome. She also gave a history of chicken pox at the age of 3 years. So PCR for Varicella Zoster virus in CSF was ordered and was positive. She was discharged home on intravenous acyclovir for 10 days and reported complete recovery.
Neurological complications due to reactivation of Varicella Zoster virus have been described extensively in immunocompromised patients and those older than 50 years but rarely in young, immunocompetent patients. Due to its indolent course, it is likely to be misdiagnosed in the latter group, especially if the cutaneous rash is absent or delayed. Also, patients often take over the counter medications like Paracetamol and Ibuprofen for headache, which may mask fever and further complicate the diagnosis.
Awareness of Varicella meningitis causing headache in young patients will promote timely diagnosis. This is imperative as it is a treatable condition that can potentially lead to complications like encephalitis, cerebral vasculitis and post herpetic neuralgia. A high suspicion for aseptic meningitis will help decrease misdiagnosis and ineffective treatment. Also, the possibility of subclinical meningitis in patients with Herpes Zoster needs to be investigated further.