throat fell really tight. They told him was throat was closing up.; Anaphylaxis/anaphylactic shock/severe allergic reaction; Swelling of the throat/throat was swelling; Trouble breathing; Itchy throat; Said that his throat felt really thirsty.; He is very upset./He is pretty devastated.; His throat started to do it again.; They said maybe it was something he ate or maybe sinuses; This is spontaneous report from contactable consumer (patient) and contactable consumer (patient's mother). A 25-year-old male patient received the first dose for BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, Lot No. EWO187) at single dose for COVID-19 immunization on 19May2021 at 12:00 or 13:00. Relevant history included Diabetes, obesity, endocrine abnormalities, genetic/chromosomal abnormalities, respiratory illness, compromised immune status and Allergies. The patient had Allergies to non-steroidal anti-inflammatory drugs that can induce anaphylactic shock, severe reaction, swelling of face and throat. Relevant concomitant drug was unknown. No history of all previous immunization with the Pfizer vaccine considered as suspect. No Additional Vaccines were Administered on Same Date of the Pfizer Suspect If applicable. No Vaccines were Administered prior vaccinations (within 4 weeks). Family Medical History was none. About 3-5 minutes after being administered the Vaccine, the patient immediately developed anaphylactic shock. He was transported via ambulance to the Emergency Room on 19May2021 where he verified he was admitted to the hospital Emergency room for about 5-6 hours and discharged from the hospital the same day, 19May2021. He was told not to get any additional doses.  He was still having swelling of the throat and went back to the ER today and was given a steroid prednisone 40mg a day for 5 days.  He was advised to take benadryl also.  He said he didn't get any IVs or anything.  He had a past medical history of anaphylactic reaction to NSAIDS.  He has been advised not to get the second dose. The patient stated the anaphylactic shock occurred with trouble breathing, throat was swelling and itchy throat. He did go into ER, they told him to just keep drinking fluids, that there was nothing else they could really do. When he was seen in the emergency room they gave him Benadryl and a steroid: Prednisone for now which he is on for the next couple of days. He was told that after 2 days or something, that after getting injected that he wouldn't have any symptoms-but he is still having those pretty severe symptoms of anaphylactic shock. Initial onset of anaphylactic shock was about 3-5 minutes after Pfizer Covid Vaccine shot was administered. Within 10-15 minutes he had swelling of tongue and throat and difficulty breathing. They called an ambulance, the ambulance took him to the Hospital emergency room where he was admitted and discharged that same date on 19May2021 after about 5-6 hours; he reported discharge time was around 16:40. They told him to come back if he had any issues that occurred over next couple of days or worsening or causing problems; to call back the nurses line. He was on a lot of Benadryl, a lot of antihistamines. When he gets off the antihistamines almost all the allergic reactions of the anaphylactic shock reoccur. This morning, 21May2021, he didn't take any Bendaryl before bed, and this morning when he woke up he was alright. After being at work like 30 minutes he felt the itchiness; scratchy throat; swelling of tongue; a little swelling of the throat; difficulty breathing. He took Benadryl and called the hotline who told him to call the Emergency room, he called the emergency room and went there. He talked to them this morning because he went to work and had issues breathing. He called and they told him to come in asap, so he went in to the emergency room; they gave him Benadryl and told him there was nothing else they could do other than him taking the steroid: Prednisone. The patient was in the hospital 3 days and will be day 4 tomorrow. He was trying to figure out how long this will last. They told him to talk to his doctor. They basically told him they were not responsible. The patient's mother reported that her son received the shot Wed 19May2021. Does not know if the Walgreen's reported this. He left there in an ambulance within 10 minutes of getting the shot. They took him to the emergency room and he got mixed information. He went back again today. They blew him off and told him maybe it was something he ate. She assumed that an allergic reaction would be about 24 hours but this is day 3. She is scared he may be taking too much Benadryl. He said he felt like he needed something to drink. Said that his throat felt really thirsty. He went back inside since his throat fell really tight. They told him was throat was closing up. They saw that his throat was swollen and they called the paramedics. Within 15 minutes they came and brought him to the emergency room.  Nobody had given him Epi. They were going to give it to him an Epi pen  but he wanted to wait for the paramedics. He was freaking out. The paramedics showed up and they were unable to give him Epi, stating he didn't have hives. He only received Benadryl. They he had to have to give him extra Benadryl because whatever they gave him in the IV because the first didn't work and his throat was still closing up. It made him feel like a drug addict asking for Benadryl.  She was not sure if they gave him Benadryl in the ambulance, knows that it was given in the emergency room. The Benadryl may have been started in the ambulance but she is not sure. They did give him oxygen in the ambulance. Clarified he was in the ER over 4 hours, but was not admitted to the hospital. They gave him steroids but forgot to send him home with steroids. He had to call to find out about getting them and they told him they forgot to send the prescription in. He was late starting the next dose of steroids. He went back to the ER today, day 3. He didn't feel too bad today and went to work. After exerting a little energy and moving around, his throat started to do it again. He didn't have Benadryl on him. He left work because he thought it was going to close up again the day he got the shot. Once he calmed down, he took Benadryl. He called the hospital to ask if this was  normal. He was told that it is not normal and was told that if he still felt bad, to come to the hospital. They said maybe it was something he ate or maybe sinuses. He spoke to one of the doctors. They had never shown him how to use an ePi pen. He does not know how long this will last. He gets scared. Treatment: Has only been taking Benadryl. He started the steroids yesterday and today. They had given him Benadryl today in the ER and he is home now. The patient visited to the Emergency room twice, first time by ambulance, confirmed he was not admitted. He was pretty devastated. The outcome of events was unknown.