The causes of reactivation are uncertain, but several potential triggers have been documented. A 2009 study showed the protein VP16 plays a key role in reactivation of the dormant virus. Changes in the immune system during menstruation may play a role in HSV-1 reactivation. Concurrent infections, such as viral upper respiratory tract infection or other febrile diseases, can cause outbreaks. Reactivation due to other infections is the likely source of the historic terms 'cold sore' and 'fever blister'.
The flares are caused when your immune system falters. This can be due to a number of reasons. Anything from daily stressors, lack of sleep, poor nutrition, weight gain, concurrent illnesses etc may cause your immune system to be distracted from the Herpes Simplex Virus (HSV) infection. The moment that happens, the virus will flare resulting in rashes, cold sores, ulcers or blisters on your body.
While some people realize that they have genital herpes, many do not. It is estimated that one in five persons in the United States has genital herpes; however, as many as 90 percent are unaware that they have the virus. This is because many people have very mild symptoms that go unrecognized or are mistaken for another condition or no symptoms at all.
"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."