First days of vacation, sun and… a herpes labial. Also known as “fever” o “lip fever” is caused by a virus that remains silent in our body until a trigger makes it wake up.
“The first contact with the culprit of this infection, which in most cases is the virus del herpes simple 1 (Hsv1), occurs at an early age. Young children are infected by adults who kiss themunaware that they are about to have cold sores or recovering from a recent relapse,” explains Stefano Veraldi, professor of the Clinical Dermatology course at the University of Milan Bicocca.
“After primary infection, usually asymptomatic in children, the virus “retreats” to the nerve ganglia closest to the site of infection, where it remains latent. Occasionally, it can reappear and give rise to relapses that manifest in the so-called “fever of the lips”, that is, cold sores”, adds Veraldi.
“The time frame in which the virus can be transmitted is short because, once the vesicles appear, the virus immediately returns to the nerve ganglia,” says Professor Veraldi, “contagion can only occur when the virus is actively replicating, through direct contact with the serum of the vesicles on the skin or mucous membranes. In addition, it is only possible to infect individuals who have not yet had contact with the virus, generally children, especially the youngest, of between 3 months and 3 years old‘.
“Just a little deficit in immune defenses for the virus to reactivate. It can occur at times of stressfor example after a trip, a gripeand at this time, especially after a excessive exposure to sunlightsays the professor.