A 10-year-old boy is brought to the emergency department due t | Uworld | Step 1

A 10-year-old boy is brought to the emergency department due to a fall while riding his bicycle. The patient hit his forehead on a concrete road barrier and sustained a laceration but did not lose consciousness. He reports no headache, nausea, vomiting, vision disturbances, or focal weakness or numbness. The patient received a tetanus vaccine at age 6. Vital signs are within normal limits. Physical examination reveals a 2-cm laceration above the left eyebrow. There are no other injuries. Neurologic examination shows no abnormalities. Prior to laceration repair with suture, lidocaine is injected in the subcutaneous tissue around the laceration. The patient reports immediate relief of pain, and there is loss of sensation to touch in the area infiltrated with the medication.