Generally, the primary infection is asymptomatic and may go unnoticed. However, if symptoms do occur, they can be quite serious. There are usually prodromal symptoms a few days before the onset (fever, weakness, burning or tingling sensation). The primary infection may present as acute gingival stomatitis in children and severe pharyngitis in adults. Sometimes fever, muscle pain, malaise and lymphadenopathy occur. Herpetic gingival stomatitis can also occur in adults, especially those who are immunocompromised.

Usually the course is favorable, with spontaneous healing in less than 15 days. LH can occur as a single occurrence or become recurrent. After the primary infection, the virus remains latent in the neurons of nearby sensory ganglia (usually the trigeminal ganglion). In some individuals, the virus remains inactive, while in others it can be reactivated after a variable period, leading to recurrent outbreaks of LH, followed by a return to latency. About a third of those infected experience at least one relapse during their lifetime.

LH is easily recognized by the individual, who often feels its impending eruption by sensations in the area where it previously appeared. These sensations include burning, tingling or itching localized to a small area, usually affecting the lips and surrounding skin. Then, a red-yellow spot quickly develops into vesicles within six hours to two days of the first symptoms. Over a few days, the vesicles rupture and form ulcers, which are then covered by a yellowish crust that eventually falls off without scarring. Lesions may also appear on the oral mucosa or skin, sometimes around the nose or cheek.

Outbreaks vary in frequency and severity, from one to two episodes per year to monthly occurrences. As individuals age, relapses tend to decrease in intensity and frequency.

In immunocompetent individuals, HSV-1 infections are usually self-limiting and rarely severe. Usually, LH disappears completely within seven to ten days, although longer durations of two to three weeks have been reported.

LH presents an aesthetic concern with potential psychosocial implications. For those who experience recurrent LH, the painful and unpleasant lesions can cause significant stress and anxiety.

HSV-1 is highly contagious and is spread through direct contact with infected individuals, their oral secretions or lesions. Indirect transmission is also possible because the virus remains viable on surfaces for several hours. Infection is most contagious during active replication but can also occur asymptomatically. Although HSV-1 infection is common, its prevalence has decreased in developed countries. Other clinical manifestations of HSV-1 infection include skin and mucosal lesions, genital herpes, eye infections, and serious systemic conditions such as encephalitis, meningitis, or respiratory tract infections.

Various triggers have been identified for LH recurrence, including exposure to sunlight, fever, menstruation, stress, fatigue, local trauma, infectious diseases, or immunosuppression. However, some relapses can occur without an identifiable trigger.

For more information please contact Grupo HPA Saude on (+351) 282 420 400.