passed out/hurting his head, his back and arms; hurting his head; his back and arms; hurt his arms; his heart felt tight; Acute syncope cause not determined; chest pain /heart pain; skin rashes; rashes or hives in his arms and legs/had rashes all over for about 2 weeks; a rash on his arm on the injection site; This spontaneous case was reported by a consumer and describes the occurrence of URTICARIA (rashes or hives in his arms and legs/had rashes all over for about 2 weeks), LOSS OF CONSCIOUSNESS (passed out/hurting his head, his back and arms), HEAD INJURY (hurting his head), BACK INJURY (his back and arms), LIMB INJURY (hurt his arms), CHEST DISCOMFORT (his heart felt tight), SYNCOPE (Acute syncope cause not determined), CHEST PAIN (chest pain /heart pain) and RASH (skin rashes) in an 18-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch no. 036b21a) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     No Medical History information was reported.   On 06-Apr-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On 07-May-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) dosage was changed to 1 dosage form. On 07-May-2021, the patient experienced VACCINATION SITE RASH (a rash on his arm on the injection site). On 08-May-2021, the patient experienced URTICARIA (rashes or hives in his arms and legs/had rashes all over for about 2 weeks) (seriousness criterion hospitalization). On an unknown date, the patient experienced LOSS OF CONSCIOUSNESS (passed out/hurting his head, his back and arms) (seriousness criteria hospitalization and medically significant), HEAD INJURY (hurting his head) (seriousness criterion hospitalization), BACK INJURY (his back and arms) (seriousness criterion hospitalization), LIMB INJURY (hurt his arms) (seriousness criterion hospitalization), CHEST DISCOMFORT (his heart felt tight) (seriousness criterion hospitalization), SYNCOPE (Acute syncope cause not determined) (seriousness criteria hospitalization and medically significant), CHEST PAIN (chest pain /heart pain) (seriousness criteria hospitalization and medically significant) and RASH (skin rashes) (seriousness criteria hospitalization and medically significant). The patient was treated with DIPHENHYDRAMINE HYDROCHLORIDE (BENADRYL [DIPHENHYDRAMINE HYDROCHLORIDE]) at a dose of 1 dosage form. At the time of the report, URTICARIA (rashes or hives in his arms and legs/had rashes all over for about 2 weeks), CHEST DISCOMFORT (his heart felt tight), CHEST PAIN (chest pain /heart pain), RASH (skin rashes) and VACCINATION SITE RASH (a rash on his arm on the injection site) had not resolved and LOSS OF CONSCIOUSNESS (passed out/hurting his head, his back and arms), HEAD INJURY (hurting his head), BACK INJURY (his back and arms), LIMB INJURY (hurt his arms) and SYNCOPE (Acute syncope cause not determined) outcome was unknown.            No concomitant medications were reported by reporter. It was also reported that patient visited neurologist, dermatologist, and cardiologist  Based on the current available information and temporal association between the use of the product and the start date of the events,   a causal relationship cannot be excluded.  Further information has been requested.   Most recent FOLLOW-UP information incorporated above includes: On 23-Aug-2021: Significant follow up appended-Event updated On 23-Aug-2021: Non-significant follow up; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events,   a causal relationship cannot be excluded.  Further information has been requested.