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'.
Your healthcare provider may diagnose genital herpes by simply looking at your symptoms. Providers can also take a sample from the sore(s) and test it. In certain situations, a blood test may be used to look for herpes antibodies. Have an honest and open talk with your health care provider and ask whether you should be tested for herpes or other STDs.
Recurrent outbreaks of genital herpes may happen, with some patients having four to six outbreaks in the span of a year. Compared to the first infection, subsequent recurrences are less painful and occur in shorter periods than the first infection. There are some patients, however, who don’t have another outbreak for many years or even once more during their lifetime.11
"When you are having an outbreak of oral herpes, symptoms usually start with a burning, itching or tingling sensation on your lips," Michael says. "This will intensify until a small rash, and then blisters, appear. These sores are commonly called 'cold sores'. The blisters are usually filled with a clear or slightly yellow liquid. Over a short time, these blisters will burst leaving a painful, raw area. These will then dry and scab over. The scabs will generally fall off after a week or two, leaving fresh clear skin beneath."