MMR rash may be caused by the adverse reaction after injection of MMR vaccine, or it may be caused by allergy to MMR vaccine, which needs to be seen according to the actual situation.
1. Adverse reactions caused by MMR vaccine: some people may have adverse reactions after MMR vaccine injection, rashes will appear on the body, usually in 6~12 days after vaccination, the symptoms are usually mild, most of them do not need special treatment, and will subside by themselves.
2. Allergic reaction: Some people may have allergic reaction to some components of the MMR vaccine after injection due to their physical condition, so a rash will appear on the body, usually within 72 hours after injection.
Rash after MMR vaccination may also be caused by other reasons, it is recommended to actively go to the hospital, to clarify what the cause is, and then targeted treatment, so as not to delay the condition.