Anaphylaxis to MMR Vaccine Mediated by IgE Sensitivity to Gelatin; Anaphylaxis to MMR Vaccine Mediated by IgE Sensitivity to Gelatin/he developed onset of facial urticaria, periorbital swelling of both eyes with redness and itching, congestion, rhinorrhea, slight cough, and itchy throat; Anaphylaxis to MMR Vaccine Mediated by IgE Sensitivity to Gelatin; This literature marketed report as received from the authors of a published literature article, titled as stated below, refers to a 19-year-old male patient in Training. At 6 years old, this patient reported having a reaction to the varicella vaccine (manufacturer unknown) (captured in MARRS # 2006USA000219) that resulted in tightness of his throat, heaviness of his chest, and vomiting. He did not require medical intervention and his symptoms gradually resolved on their own. He reported a suspected pork allergy, as he had immediate tightness in his chest after eating large amounts of pork. He also reported a suspected gelatin allergy, as he had immediate tightening in his throat after eating gummy bears as well as hives on his face after using gelatin-containing face creams. He has never had a reaction to penicillin, but he could not recall ever taking penicillin in the past. He also had a history of seasonal allergic rhinitis.  During in-processing he did not have records of previous immunizations, and a repeat measles, mumps, and rubella (wistar ra 27-3) virus vaccine, live (manufacturer unknown) (MMR) vaccine was recommended. He was given an intramuscular (IM) penicillin injection 15 minutes prior to the MMR vaccine, but had no immediate symptoms at that time. About 23 minutes after getting the MMR vaccine (dose, route of administration, lot # and expiry date were not specified), he developed onset of facial urticaria, periorbital swelling of both eyes with redness and itching, congestion, rhinorrhea, slight cough, and itchy throat. He was diagnosed with anaphylaxis and promptly treated with an epinephrine 0.3 mg intramuscular (IM) injection and 25 mg of diphenhydramine intravenously. He was then taken to the emergency room (ER) where his symptoms continued to improve over a 6-hour observation period. He was discharged back to training on a 5-day course of prednisone 50 mg daily, diphenhydramine 25mg every 8 hours as needed, and ranitidine 150 mg twice daily as needed with no further reactions. He was subsequently referred to the allergy clinic for further investigation to determine if his allergic reaction was from the penicillin injection or from the MMR vaccine. The differential diagnoses considered included possible IgE-mediated hypersensitivity to MMR vaccine, pork allergy, gelatin allergy, and/or penicillin allergy. The patient's history was consistent with a possible IgE-mediated hypersensitivity to the MMR vaccine and/or the penicillin IM shot. His past medical history was also concerning for a possible allergy to gelatin and pork. Antibody titers to measles, mumps, and rubella were first obtained to determine if patient still required another MMR vaccine, and serology testing was also obtained to gelatin, pork, and cat. Labs showed patient was rubella immune and mumps immune, but still measles non-immune. His serology testing also showed that he was positive for gelatin (Ab IgE 1.20 kU/L) but negative for pork (Ab IgE <0.35 kU/L). Per Advisory Committee on Immunization Practices (ACIP) guidelines, this patient still required one additional dose of the MMR vaccine, as he was in a postsecondary institution with multiple close contacts. Skin prick testing was completed using saline as a negative control, histamine as a positive control, and the MMR vaccine and was initially found to be positive to the MMR vaccine. Per the practice parameter's graduated dosing protocol, this patient was first given a 0.05 mL injection of the vaccine at 1:10 dilution and was observed for 15 minutes without issues. He was then given a 0.05 mL injection of the vaccine at full strength, at which time, he developed sudden onset of periorbital swelling of both eyes with redness and itching congestion, and sneezing. He denied associated lightheadedness, syncope, shortness of breath, wheezing, cough, vomiting, abdominal pain, or diarrhea. Due to concern for anaphylaxis, he was given one dose of IM epinephrine 0.3 mg, one dose of cetirizine 10 mg orally, and one dose of ranitidine 150 mg orally. 1520 minutes later, he reported feeling better but continued to have mild left periorbital swelling, so an additional dose of cetirizine 10 mg was given with good response. He was observed for 1 hour and then discharged after complete resolution of his symptoms. The results of serology, skin prick testing, and vaccine challenge showed that this patient's previous anaphylactic reaction was likely due to the MMR vaccine and not the penicillin shot. Serum IgE testing further suggests that the reaction was due to an IgE-mediated hypersensitivity reaction to the gelatin component in the vaccine. This patient would still require a second dose of MMR in order to remain in the military. However, he was able to contact his family who helped locate documents that showed he actually did have two previous MMR doses administered in childhood. As he now had three total documented doses of MMR (two from childhood and one during in-processing), no further doses of the vaccine were needed, even if subsequent MMR titers were found to be negative or equivocal. The data suggests that the hydrolyzed gelatin added to the vaccine was the cause of his anaphylactic reaction. The outcome of the events was recovered. The author considered the events to be related to measles, mumps, and rubella (wistar ra 27-3) virus vaccine, live (manufacturer unknown).   A copy of the published article is attached as further documentation of the patient's experience.  This is one of two reports derived from the same literature article.   Literature report: Sender's Comments:  IT-009507513-2006USA000219: