Red dots (Petechiae) on my neck after vomiting?

Last night I had a little too much to drink and threw up. Today I discovered petechiae all over the front of my neck and some on my face. I read that it was common to find it on your face after vomiting violently, but I can't find anything about having it on my neck. Wikipedia says that there are a lot of other causes for petechiae including congenital syphilis which really worries me because I have had unprotected with a few partners in the past (irresponsible, I know). Should I be worried or is petechiae on the neck after a night of vomiting also common?