Herpes simplex labialis
Cold sores are caused by the herpes simplex virus (HSV). There are two types of herpes simplex virus: HSV-1 and HSV-2. Both virus types can cause sores around the mouth (herpes labialis) and on the genitals (genital herpes). A cold sore is usually caused by HSV-1 and HSV-2 is the main cause of genital herpes. The herpes simplex virus usually enters the body through a break in the skin around or inside the mouth.
It is usually spread when a person touches a cold sore or touches infected fluid. Such as from sharing food and utensils with an infected person, through kissing, close personal contact. A parent who has a cold sore often spreads the infection to their child in this way. Cold sores can also be spread to other areas of the body/face.
Impetigo and a cold sore are often confused. A cold sore is caused by the herpes simplex virus. Impetigo is a highly contagious skin infection and it is caused by bacteria.
Impetigo, which is one of the most common skin infections among kids, usually produces blisters or sores on the face, neck, hands, and nappy area. This contagious superficial skin infection is generally caused by one of two bacteria: Staphylococcus aureus or Streptococcus pyogenes (also called group A streptococcus, which also causes strep throat). Methicillin-resistant Staphylococcus aureus (MRSA) is also becoming an important cause of impetigo.