Reporter states this rash and hives quickly turn into a Dermatographia; on Friday night and Saturday Rash started; on Wednesday start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable; start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable; Son received the booster dose on 20Dec2021, right after and for 24 hours patienthad vomiting and diarrhea for 24 hours; Son received the booster dose on 20Dec2021, right after and for 24 hours patienthad vomiting and diarrhea for 24 hours; throat tightening; hives, welts; welts a low grade fever; chills; muscle aches; joint pain; This spontaneous case was reported by a consumer and describes the occurrence of MECHANICAL URTICARIA (Reporter states this rash and hives quickly turn into a Dermatographia), THROAT TIGHTNESS (throat tightening), URTICARIA (hives, welts), GASTROOESOPHAGEAL REFLUX DISEASE (on Wednesday start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable) and ABDOMINAL DISCOMFORT (start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable) in a 19-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 032H21A, 046B21A and 002B21A) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.    Co-suspect product included non-company product LEVOCETIRIZINE DIHYDROCHLORIDE (ALLEGRA [LEVOCETIRIZINE DIHYDROCHLORIDE]) for an unknown indication.    No Medical History information was reported.   On 18-Mar-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 18-Apr-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 20-Dec-2021, received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On an unknown date, the patient started LEVOCETIRIZINE DIHYDROCHLORIDE (ALLEGRA [LEVOCETIRIZINE DIHYDROCHLORIDE]) (unknown route) 1 tablet per 3 days. In December 2021, the patient experienced THROAT TIGHTNESS (throat tightening), URTICARIA (hives, welts), PYREXIA (welts a low grade fever), CHILLS (chills), MYALGIA (muscle aches) and ARTHRALGIA (joint pain). On 20-Dec-2021, the patient experienced DIARRHOEA (Son received the booster dose on 20Dec2021, right after and for 24 hours patienthad vomiting and diarrhea for 24 hours) and VOMITING (Son received the booster dose on 20Dec2021, right after and for 24 hours patienthad vomiting and diarrhea for 24 hours). On 22-Dec-2021, the patient experienced GASTROOESOPHAGEAL REFLUX DISEASE (on Wednesday start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable) and ABDOMINAL DISCOMFORT (start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable). On 24-Dec-2021, the patient experienced RASH ( on Friday night and Saturday Rash started). On 31-Dec-2021, the patient experienced MECHANICAL URTICARIA (Reporter states this rash and hives quickly turn into a Dermatographia). The patient was treated with CLARITHROMYCIN (KLARICID [CLARITHROMYCIN]) from 06-Jan-2022 to 12-Jan-2022 at a dose of 1 tablet in the morning. In December 2021, DIARRHOEA (Son received the booster dose on 20Dec2021, right after and for 24 hours patienthad vomiting and diarrhea for 24 hours) and VOMITING (Son received the booster dose on 20Dec2021, right after and for 24 hours patienthad vomiting and diarrhea for 24 hours) had resolved. At the time of the report, MECHANICAL URTICARIA (Reporter states this rash and hives quickly turn into a Dermatographia), THROAT TIGHTNESS (throat tightening), URTICARIA (hives, welts), GASTROOESOPHAGEAL REFLUX DISEASE (on Wednesday start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable), ABDOMINAL DISCOMFORT (start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable), RASH ( on Friday night and Saturday Rash started), PYREXIA (welts a low grade fever), CHILLS (chills) and ARTHRALGIA (joint pain) outcome was unknown and MYALGIA (muscle aches) had resolved.        For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter considered MECHANICAL URTICARIA (Reporter states this rash and hives quickly turn into a Dermatographia) to be related. No further causality assessments were provided for THROAT TIGHTNESS (throat tightening), URTICARIA (hives, welts), GASTROOESOPHAGEAL REFLUX DISEASE (on Wednesday start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable), ABDOMINAL DISCOMFORT (start experiencing GERD patient felt like a rock in his Stomach, makes him feel very uncomfortable), DIARRHOEA (Son received the booster dose on 20Dec2021, right after and for 24 hours patienthad vomiting and diarrhea for 24 hours), RASH ( on Friday night and Saturday Rash started), PYREXIA (welts a low grade fever), CHILLS (chills), MYALGIA (muscle aches), ARTHRALGIA (joint pain) and VOMITING (Son received the booster dose on 20Dec2021, right after and for 24 hours patienthad vomiting and diarrhea for 24 hours).    Patient reaction was not related to an allergic reaction but it's an over reaction to the immune system. Reporter stated that patient doesn't have any food allergies or any allergies, mention patient never had any health problem.  Concomitant medications was not reported. Treatment drug  Azisel administered as 1 Tablet per night since 6-jan-2022. Some of this Symptoms were shot term lasted until Monday patient experienced muscle ache for a few more days then ended, but since 31Dec2021 and ongoing patient develop a rash develop hives,  Reporter states this rash and hives quickly turn into a Dermatographia, and that it's related to the booster dose.