Generally, the primary infection is asymptomatic and can go unnoticed. However, if symptoms do occur, they can be quite severe. 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 there is fever, muscle pain, malaise, and lymphadenopathy. Herpetic gingival stomatitis can also occur in adults, especially those who are immunocompromised.

Typically, the course is favourable, 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 reactivate after a variable period, leading to recurrent outbreaks of LH, followed by a return to latency. Approximately one-third of those infected experience at least one recurrence during their lifetime.

LH is easily recognizable by the individual, who often senses its impending eruption through sensations in the area where it previously appeared. These sensations include burning, tingling, or itching localized to a small area, typically affecting the lips and surrounding skin. Subsequently, a red macule quickly develops into vesicles within six hours to two days after the initial 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 occur on the oral mucosa or skin, occasionally around the nose or cheek.

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

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

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

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

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

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