When herpes flares up again, it is called a "recurrence" or "outbreak." Herpes does not always recur, and if it does recur, the timing and severity are different from person to person. Some people rarely have recurrences. Others have them often. Herpes is most likely to recur in the first year after infection. Recurrences may be more frequent for people with weakened immune systems.
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.
The cell this virus targets is the B lymphocyte. These cells mature in the bone marrow and are a type of mononuclear leukocyte cells - white blood cells with a one-lobed nucleus. The incubation period for the Epstein – Barr Virus (EBV) is about 30 to 50 days, and patients typically have enlarged lymph nodes and spleens. Some patients have signs of hepatitis.
Although it’s not caused by either the HSV-1 or HSV-2 virus, herpes zoster falls under the umbrella of herpes diseases. Also known as shingles, it’s an infection caused by the varicella-zoster virus, and is characterized by the development of painful skin rashes on one side of the face or body.23 These rashes are red patches of fluid-filled blisters that tend to crack easily.24,25
According to a study in the New England Journal of Medicine, more than 30% of pregnant women in the United States have genital HSV. During pregnancy, people are immunocompromised so that their body doesn’t fight the fetus as a foreign invader. And when a person’s immune system is weakened, they are more likely to have herpes outbreaks. According to Cullins, “Pregnancy is the time period when [a provider] really wants to know whether or not the person has had herpes in the past,” so they can protect the pregnant person and their infant from a herpes infection.
A person may show symptoms within days after contracting genital herpes, or it may take weeks, months, or years. Some people may have a severe outbreak within days after contracting the virus while others may have a first outbreak so mild that they do not notice it. Because of these possibilities, it can be difficult for people to know when and from whom they may have contracted the virus.