The HSV viruses multiply in the human cell by overtaking and utilizing most of the human cells functions. One of the HSV steps in multiplication is to take control of the human cell's nucleus and alter its structure. The altered nucleus (enlarged and lobulated or multinucleated) is what actually is used to help diagnose herpes simplex infections by microscopic examination. The reason sores appear is because as they mature the many HSV particles rupture the human cell's membrane as they break out of the cell.
Consequently, you may already have the virus. A doctor can determine this with a blood test for Herpes 2 (Ig), a type-specific immunoglobulin. If you are already infected, you won’t be at risk for a new infection — you and your boyfriend already share the virus. But knowing your herpes status will tell you whether you are capable of infecting a future partner.
"Oral herpes is an infection found in the mouth, or on and around the lips, caused by the Herpes Simplex Virus (HSV)," Michael explains. "There are two types or strains of this virus called HSV1 and HSV2. Usually, the HSV1 strain infects the mouth and lips, and the HSV2 strain infects the genitals. It is however possible for HSV2 to infect your mouth and lips."