Once a person is infected, there are no symptoms for anywhere between 2 days to 2 weeks. This is known as the incubation period and is the time during which the virus multiplies profusely. The first symptoms that are seen are the small fluid-filled blisters known as vesicles. This arises as the virus starts destroying cells at the site and causes intense localized inflammation. These small vesicles or sometimes the larger bullae may either burst resulting in ulcer or heal completely with no scarring. The virus may also travel from the site of infection and “hides” by the sensory dorsal root. Here it remains latent until is it is reactivated.
Signs and symptoms of dehydration usually warrant going to a hospital's emergency department. Infants, especially under 6 weeks of age or if the infant appears to slow urine output or decrease fluid intake, should be evaluated by their pediatrician or in an emergency center if oral sores appear. Individuals with immune suppression (for example, patients undergoing chemotherapy, HIV patients, or cancer patients) should contact their doctors if they suspect a HSV-1 infection.