Patient is a 40-year-old female patient (accompanied by her husband and her disability service dog) and was vaccinated at the mall High Volume Vaccination Site on 12/6/2021; and on this date the patient was vaccinated at 11:54am by RN in which she received her THIRD dose in the series for Moderna (Lot#027H21B) related to her immunocompromised status.   It was reported to this writer, Charge RN that at clinical check-in it was noted by clinical staff that patient confirmed to check-in screening RN that she had no issues with her initial first and second Moderna vaccinations. Per patient husband report, following vaccination the patient ambulated safely to post-vaccination observation area without issue and was a 30-minute wait related to her extensive allergy history. However, it was reported to this writer, Charge RN that after 15-20 minutes at around 12:29pm in post-vaccination observation the patient?s husband stated that his wife said she ?feels like a small, dry marble in my throat?. At this same time post-vaccination observation clinical staff member, RN was rounding as the patient began to rub her neck to the left mandibular area of her face. RN reported to this writer, Charge RN that at that time she had visually observed that the patient was rubbing her neck and holding her throat, so she checked in with the patient immediately who confirmed ?feels like a marble under the left side of my neck?. Furthermore, per  RN she also assessed following this patient complaint and noted visible swelling to left mandible area of patient face underneath chin. RN immediately notified this Charge RN who immediately responded to the incident. Patient was safely escorted to the private medical cot area with her husband and service dog. Patient was assessed by Charge RN while sitting on the side of medical cot and was visibly anxious and her skin was flush. Patient stated that her tongue was starting to tingle, and she felt that the ?marble? was enlarging and getting worse, patient speech however was still clear, and no slurring noted.   Another clinical provider RN also responded to the incident at this time in medical cot area to assist. RN assisted with patient swallow assessment with small cap-size amount of water, patient tolerated with no coughing or difficulty noted. Patient was also able to take a sip of her water without difficulty. Patient and patient husband strongly verbally refused Epi-pen for suspected anaphylaxis, so immediately following passing RN swallow assessment RN and Charge RN following 2 nurse medication verification administered per medical director provider standing orders following patient verbal consent, allergy screening, and patient education a total of 25mg Benadryl Oral Liquid at 12:35pm. Patient swallowed standing ordered Benadryl 25mg Oral Liquid without difficulty, coughing, or aspiration noted. Again, patient had strongly verbally refused Epi-pen and wanted RNs to safely assess swallow beforehand as noted.   Patient then informed staff that she had severe history of anxiety and PTSD that increased during the pandemic and always needed her disability service dog with her. She was able to still speak at this time without difficulty, and with no slurred speech or drooling noted, but she remained visibly anxious and she stated her tongue still felt ?tingly?.   Patient blood pressure checked at 12:36pm and it was noted right arm sitting BP 142/110 with respirations 24. Patient and her husband strongly refused staff calling 911 for further assistance and patient was still able to breathe. At 12:43pm about 7 minutes after one-time medication administration of standing ordered Benadryl 25mg Oral Liquid, the patient reported that she noticed that the tingling and ?marble feeling? in her neck were beginning to subside but that her neck was still tender. Patient safely laid supine while head elevated on multiple pillows on medical cot and tolerated this position well with no coughing or signs of aspiration noted. This supine position with head elevated on pillows on medical cot did not restrict breathing and helped to calm the patient?s anxiety. Patient began to calm more, with vitals reassessed around 12:47pm, and laying vitals check showed an improved right arm BP 128/84, HR 98, SPO2% 100, RR 18. At 12:59pm vitals re-checked and stable HR 96, SPO2 99%, RR 16. At the military time of 1302 patient verbalized with no slurring or difficulty speaking that the ?thick marble? feeling in her throat had completely subsided. Patient stated that the tingling sensation of her tongue was completely gone and back to normal for her.   Patient and patient husband educated by this Charge RN to follow-up with her primary care provider this week so that they can further assess and add to this incident to her medical history as indicated by her provider. She was also instructed to follow-up with her medical provider before she returns for her booster vaccination in 6 months since today was her THIRD dose in the Moderna vaccination series related to her immunocompromised status. Patient and patient husband both verbalized understanding, and patient stated that she would check with her doctor about also obtaining an Epi-pen since she didn?t have one given her extensive allergy history which RN recorded from patient and her husband as follows (Amoxicillin, Penicillin, Sulfa, Cephalosporins ? all causing Anaphylaxis reactions in the past). Patient and her husband also educated by RNs that if tingling symptoms return to call 911 immediately; patient and patient husband verbalized understanding. Patient also stated that if she can safely swallow if her symptoms returned that she wanted to take Benadryl oral liquid before help arrives and she asked her husband to stop by the store on the way home from the vaccination clinic to pick some up. Patient husband agreed.   At 1309 patient swallow normal with no coughing noted, skin within defined limits with no flushing of skin noted, patient denied tingling of tongue, and denied any neck discomfort or ?marble? sensation. Patient able to safely swallow water from her water bottle without issue. RNs assessed that there was no swelling noted to tongue, neck, or throat. At 1313 time patient verbalized she felt safe to stand at side of medical cot, patient denied dizziness or lightheadedness when standing. Anxiety completely subsided. Patient began laughing and joking with staff. Patient declined further assessment and emergency personnel assistance. At 1322 patient walked from medical cot to clinic entry door with Charge RN present along with her husband and service dog present; this RN noted patient gait stable, no complaints of difficulty breathing, weakness, or dizziness upon ambulation, respirations remained within defined limits. Patient safely exited the clinic in the care of husband and service dog.