Ms. K, aged 16 years, presented to the emergency department (ED) after being seen by her primary-care clinician 48 hours earlier for an annual physical exam and immunization update. Physical assessment was unremarkable at that time. During that exam, Ms. K received her third dose of the human papillomavirus (HPV) vaccine, Gardasil. Approximately one hour after administration, Ms. K’s mother found her unconscious and drooling and called 911. 

Ms. K was seen in the local ED, where this was diagnosed as a transient reaction to the immunization. Following her discharge, Ms. K developed headache, photophobia, nausea and an unsteady gait. Since falling unconscious, the teen reported a headache on a pain scale of 7/10, photophobia, dizziness and difficulty walking. Ms. K’s pediatrician referred her to a regional pediatric center for further evaluation.


Ms. K was an active teenager and honor-roll student who worked in a restaurant on weekends. She lived at home with both her parents and a younger healthy sibling. Ms. K’s medical history was significant for polycystic ovaries and irritable bowel syndrome. She had been healthy prior to the physician visit two days prior. All her immunizations were up to date, and family history was negative for any medical conditions. Ms. K was not taking any medications and denied drug or alcohol use


Ms. K’s vital signs in the ED were as follows: temperature 98.7° F, pulse 73 beats per minute (BPM), BP 110/69 mm Hg, respiration rate 20 inspirations per minute, pulse 93 BPM with oximetry 100% on room air. BP was 115/63 lying down, 117/73 while sitting, and 60/40 while standing. The teen appeared to be well-developed and well-nourished, but her behavior was anxious and tearful.

Ms. K’s lungs were clear and her heart sounds were normal, but she complained of nausea. Her extremities were warm, and an unsteady gait was apparent. A detailed neurologic exam revealed that cranial nerves I-XII were intact, and the patient exhibited rapid, alternating movements that were coordinated and smooth. Ms. K’s reflexes were intact, and there was evidence of a symmetrical response to pain with cutaneous hyperesthesia in soft-tissue areas. There were no meningismus signs.

Laboratory Data and Diagnosis

A CT scan of the head, brain and sinuses was ordered to rule out increased intracranial pressure; the findings were normal. The following blood panels were performed and all were negative: a complete blood count, comprehensive metabolic profile, Epstein-Barr virus, erythrocyte sedimentation rate and blood culture. The teen’s ECG was normal.

Pediatric neurology was called in on consultation and advised that Ms. K be admitted to the hospital for observation. Ms. K’s diagnosis on her admission form included post-Gardasil-administration headache and syncope, vasovagal orthostatic hypotension, rule out sinusitis, rule out meningitis, and rule out transverse myelitis. 

This article originally appeared on Clinical Advisor