From ED and Hospital notes: Patient is a 58 y.o. male with history most notable for esophageal reflux. Presents by EMS for allergic reaction after flu shot this morning. On arrival he is mildly tachycardic with a respiratory rate of 20, SPO2 100%. He has significant periorbital swelling. The uvula and surrounding structures, posterior pharynx are edematous both the airway remains patent. Voice is muffled. Breath sounds are clear without wheezing. He is able to rest in bed comfortably without tachypnea. Heart sounds normal, mildly tachycardic rate. Abdomen nontender. Skin without rash appreciated. As reports that his symptoms are slightly worsening and I suspect the previous epinephrine is wearing off, 0.3 mg IM epinephrine 1:1000 was given. In addition, he received 50 mg of IV BENADRYL and 20 mg of IV PEPCID. He just received 10 mg IV dexamethasone by EMS. A liter of saline was initiated. He reports subjective improvement after IM epi, but there is no visible change in the appearance of his pharynx.  He is able to lie back, rest comfortably, breathing without visible difficulty. There is no wheezing or stridor. Handling secretions without difficulty. Will trial the addition of racemic epi to see if this provides further benefit; slightly improved. On multiple subsequently rechecks, no significant change. Continues to have posterior pharyngeal edema, but this is not appear to be progressing, states that his breathing is doing well. Voice remained somewhat muffled. Given that he required multiple doses of epinephrine and continues to have swelling I do feel he mandates hospital admission. Discussed with Dr. who accepts. Patient and wife are agreeable. It does appear that this represents anaphylaxis secondary to flu vaccine (Sanofi Pasteur Influenza Quadrivalent PF Vaccine). There have been no other recent medication, food, or environmental exposures that would otherwise explain his symptoms. The time relationship is also highly suggestive. While in the emergency department remained rather stable. His symptoms have now been ongoing for about 6 hours which is somewhat reassuring from the standpoint of stability. Hospital Course by Problem: Angioedema after flu shot. Improved after DECADRON 10 mg, two IM epi injections, dose BENADRYL and dose PEPCID as well as one racemic epi treatment. Pt thought he was having recurrent sxs overnight, but no visible swelling externally or in oropharynx. This am his phonation is normal, oropharyngeal exam not revealing of any swelling, tongue normal. No stridor on exam, lungs clear. Mild tachycardia and HTN presumably 2/2 epinephrine and stress. HR nl today. Bedside swallow exam ok, has eaten two meals since admission. Continue BENADRYL 4 days and SOLUMEDROL for 3 more days to be on safe side since he is going to a remote wedding on Saturday. Will prescribe epi pen at discharge. Discharged 9/12/2018. Periorbital edema. He and his wife told staff that this was new, but told admitting doc it is chronic. U/A negative for protein. Other: H/o kidney stones; Irritable bowel syndrome; Low back pain, chronic; Obesity; Hyperlipidemia. Notable Labs/Procedures/Imaging: CBC, Renal panel negative except hyperglycemia after DECADRON and mild hyponatremia.