From ED Note: 12 year old male with PMH of asthma on flovent, food allergies with epi-pen (has not required this) and pre-syncope/syncope who presents with concern for loss of consciousness and possible seizure-like activity following a COVID vaccine.   Mom notes that he was in his usual state of health when he presented to COVID clinic to get his first vaccine. He got the Pfizer vaccine, seconds after getting in his left arm, mom noted that he looked very "wide eyed" and distraught.  She notes that he slumped forward and had lost consciousness for approximately 5 seconds.  She noticed shaking movements in his right arm and bilateral lower legs.  She notes that his left arm was against her and therefore cannot comment on it.  She notes that his eyes were closed.  No tongue biting and no incontinence.  No secondary trauma.  She notes that when these 5 seconds were over he then had a period for about 30 minutes where he looked pale and was breathing heavy but was alert and answering questions.  She notes that he has had presyncopal episodes and episodes of feeling faint when getting flu shots in the past.  However, this time she noted that he had shaking which made her nervous for possible seizure activity.  Patient denies any chest pain or headache prior to the symptoms.  She came via ambulance for further evaluation.   On arrival, he reports that he feels 90% back to his baseline.  He notes that he does not feel quite ready to run around yet however denies any pains or discomforts, headache, weakness, numbness, or tingling.   He had eaten a full breakfast prior to getting the shot.  He had a normal night sleep and a normal day yesterday per mom.   Medical History: as above  Surgical history: none Family History: Reviewed and no pertinent related family hx pertaining to this visit Social History: Lives with family  Allergies: food allergies  Medications: flovent, epi-pen Immunizations: Up to date  Medical Decision Making  12 year old male with PMH of asthma on flovent, food allergies with epi-pen (has not required this) and pre-syncope/syncope who presents with concern for loss of consciousness and possible seizure-like activity following a COVID vaccine.  On arrival, he was alert, well-appearing, in no acute distress.  His vital signs were normal for age on room air.  His physical exam was very reassuring as above with a normal neurologic and cardiac evaluation.   Differential includes vasovagal/syncope in the setting of a known stressful trigger vs seizure given report of shaking in his extremities.  We feel the latter is significantly less likely given the timeline of the events.  Has no known seizure activity nor any triggers per history (fever, trauma, etc.).  He also has a normal neurologic assessment. At this time we will defer neurology consults given low concern for seizure.  It is possible that this represents a side effect of the vaccine however we also feel that this is less likely given the fact that his symptoms have been seconds after receiving the vaccine.  Nonetheless we reported the symptoms to the pharmacist who recorded it in the database.  We attained an EKG showing a known incomplete right bundle branch block (unchanged from 2013) and a slightly prolonged QTC of 477 (previously 451).    I encourage patient to stay well-hydrated, well rested in the setting of his suspected syncopal episode this morning.  I also suggested that for further vaccinations, that he lay down on the table and drink/eat well prior.  We provided strict return to ED criteria in the setting of worsening symptoms. All questions were answered at the time of discharge. Mom verbalized her understanding and agreement of the plan. He was discharged in a stable condition with mom at side.    **After patient was discharged, cardiology called the follow-up team due to the prolonged QTC to ensure that we were aware.  I contacted the patient's PCP to do a follow-up EKG in 1 month's time.