felt like "ants biting my neck".; allergic reaction; my neck has a larger bump; not as itchy, still slightly in some areas; slightly more swollen today but no rash just what looks like a giant mosquito bite; This is a spontaneous report from a contactable consumer (patient). A 24-years-old non-pregnant female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Formulation: Solution for injection, Batch/Lot Number: not reported) dose 2, via an unspecified route of administration, administered in Arm Left on 08Apr2021 at 13:00 (at the age of 24-years-old) as dose 2, single for covid-19 immunisation. Medical history included Chronic joint pain/ arthritis of some sort. Patient had no known allergies. There were no concomitant medications. Historical vaccine included bnt162b2 on 18Mar2021 at 12:00 via unspecified route as dose 1 in Left arm for covid-19 immunisation. On 08Apr2021 at 13:00,  In less than 15 mins from recieving her second dose the patient felt like "ants biting my neck", On site Doctor confirmed it was an allergic reaction. Her neck has a larger bump, not as itchy, still slightly in some areas. Therapeutic measures were taken as a result of events. Patient received no other vaccine in four weeks. Other medications in two weeks included benadryl after allergic reaction to 2n. Staff could only find IV Benadryl, Which they didnt want to administer since she would be driving herself home. So they monitored her for 30mins since shot was administered. She did not scratch at it, and it appeared to have decreased in intensity. So she was released with strict orders to buy benadryl and go straight home and take it and she did it. She just woke up and her neck has a larger bump than yesterday. But she was not as itchy, still slightly in some areas, but nothing like yesterday. No heart palpitations/ irregularities. Patient had no covid prior vaccination. Patient did not test for covid post vaccination. The doctor states that the reaction was very minor and they monitored her for 15 more minutes and then let her leave to go get oral Benadryl and then go straight home. She confirms that they monitored her a total of 30 mins. They released her because she wasn't experiencing heart palpitations she states. She also states that after her first dose she started receiving headaches every day and that she is usually the type that doesn't get headaches but once or twice a year. So it is odd for her to have headaches every day. She states that the lot number for the first dose is: # which she received on 11Mar2021. She states that her neck looks slightly more swollen today but no rash just what looks like a giant mosquito bite. She states that it is still slightly itchy but not as severe as yesterday. She states that they only told her to take one Benadryl, and she isn't sure what to do. Caller was referred to her primary care for treatment options. She wants to know should be aware of it or if it doesn't go way should she go to urgent care. Should she be concern if the bump got bigger. It doubled the size on kind of the area that she might have been scratching. Patient stated that she took a Benadryl and she is still itchy. Lot number and expiration not retrieved due to not being a Pfizer product. Treatment was given for the event. The patient self administered benadryl at home as treatment. Outcome of the events were recovering.   This follow-up is being submitted to notify that the lot/batch number is not available despite the follow-up attempts made. Follow-up attempts completed. No further information is expected