Non-invasive Dental Prophylactic Cleaning as a Possible Trigger of Symptomatic Recurrent Herpes Labialis

Objectives: By the fifth decade, 90% of the American population is exposed to the herpes simplex virus (HSV-1, HSV-2) with 20-40% that experience episodes of recurrent herpes labialis (RHL). There is evidence supporting an increase in HSV-1 shedding following surgical and non-invasive dental treatments. The aim of this study was to see if dental prophylactic cleaning, a non-invasive procedure, could trigger an outbreak of RHL.
Methods: Thirty adults were enrolled in this single-arm trial and twenty-seven completed the study. Each subject had five visits. In the first visit, saliva, blood and urine samples were collected to verify that they were HSV positive. In the second visit, all were given dental prophylactic cleaning in the hygiene department at the SDM. Following the appointment, they were instructed to record any prodromal symptoms and RHL eruption based on a scoring system, along with the time and date. Subjects were called in for three more visits, ranging 3-7 days apart, to monitor changes. Saliva samples were obtained at each visit for serology testing.
Results: Out of 27 people, two (7.4%) had an outbreak of RHL after the dental procedure. One subject reported inflammation on the labial vermillion by the fourth visit, seven days after the prophylaxis. Six days later, at the fifth visit, the lesion had healed and inflammation indicative of new sores was present at the same site.
The second subject reported vesicle formation at the third visit, three days after the prophylaxis. Four days later, at the fourth visit, scabbing was present at the site of the lesion. Seven days later, at the fifth visit, the lesion had resolved.
Conclusions: Non-invasive dental procedures, like dental prophylactic cleaning, can trigger an outbreak of RHL in HSV positive patients. This finding is consistent with results from several studies, summarized in the Table. The two subjects that experienced vesicle formation reported that they normally have 2 and 4 episodes in a year. Going to the dentist apparently increased the number of episodes. A seemingly harmless dental procedure like a prophylactic cleaning can be stressful enough to trigger an outbreak of RHL. This information sheds light on a possible side effect of treatment on seropositive patients.