Hi I have a one 1/2 month old son and yesterday I caught one of my friends kissing him in the mouth he now has a bump. Hi I have a one 1/2 month old son and yesterday I caught one of my friends kissing him in the mouth I told her not to cause I don't know

Without. Without examining your son and seeing the bump, it's impossible for me to be able to tell what it is. Babies get rashes all the time and many of them are harmless. If you are not sure what to make of the bump on his lip, take him to his doctor. They will be able to tell you if it is of any concern. Even if it is a cold sore, he will more than likely be fine. Cold sores or fever blisters are caused by herpes simplex virus type 1 (hsv-1) and are extremely common. Most people become infected as an infant or small child when kissed or by sharing eating utensils with an adult who has the virus. The virus is most contagious when someone has a cold sore, but can still be passed along by someone who does not. Many people do not even know that they are infected because the virus can "hide out" in the nerve cells for very long periods of time - for some people it hides out forever and they never get a cold sore. For others, the virus can "wake up" and that's when a cold sore happens. No one knows exactly what causes a cold sore to appear - sometimes stress, illness, fevers, colds, sunlight, cold weather, menstruation, certain foods, allergies, you name it! They usually last 7-10 days and are more of an annoyance than a danger unless you have a weakened immune system or contract a bacterial infection on top of the cold sore.