Cold sores (herpes labialis) are small blisters caused by the highly contagious herpes simplex virus type 1 (HSV-1). If you have an upcoming dental appointment and notice an active cold sore—meaning it is blistering, weeping fluid, or newly forming—you must contact your dental office immediately to reschedule. Proceeding with treatment during an active outbreak poses significant risks to your health, comfort, and the dental staff.
Why Active Cold Sores Mandate Rescheduling
The primary reason to postpone treatment is the high risk of viral transmission during the active stage. When a cold sore is weeping, the fluid contains a high concentration of the HSV-1 virus, making it contagious through direct contact or aerosols. Manipulating the mouth and lips during a procedure can spread the virus to the dental team, other patients, and equipment. Dental procedures generate fine sprays of water and air, which can aerosolize the virus, contaminating the surrounding environment.
Continuing with treatment also compromises your own health and comfort. The stretching and manipulation of the lips required for dental work can cause the fragile lesion to tear open and bleed. This physical trauma can lead to autoinoculation, spreading the virus to other susceptible areas, such as the eyes, potentially causing ocular herpes. Physical irritation or trauma to the area can also worsen the existing lesion or trigger new ones, significantly delaying healing.
Defining the Safe Stages for Treatment
The risk of contagion decreases significantly only once the lesion is fully crusted and dry. The initial stage, called the prodrome, involves a tingling or burning sensation before the sore appears, and the virus is already contagious. The most infectious period includes the vesicle stage (fluid-filled blisters) and the ulceration stage (blisters burst and weep).
It is safe to return for non-emergency dental treatment only when the cold sore has completely entered the crusting or healing stage. This means a firm, dry scab has formed over the entire lesion, with no weeping or fluid present. Most dental practices recommend waiting until the cold sore is fully healed, typically 7 to 14 days after the initial appearance, to ensure the contagious period has passed. If the sore is still an open ulcer or actively oozing, the appointment must be rescheduled.
Communicating with Your Dental Office
Upon noticing the first sign of a cold sore—even the initial tingling sensation—call your dental office immediately to reschedule. Giving advance notice allows the office to manage their schedule and potentially offer the time slot to another patient. Simply explain that you need to postpone non-emergency treatment until the lesion is fully healed.
Managing Frequent Outbreaks
For patients who experience frequent outbreaks, inform the dental team of your history. A dentist or physician may prescribe an antiviral medication, such as valacyclovir, to be taken preventively before a scheduled procedure. This can reduce the risk of an outbreak being triggered by the treatment itself.
Dental Emergencies
If you have a true dental emergency, such as severe pain or trauma, the office must be informed of the cold sore. They can then take extra precautions, such as protecting the lesion with a dental patch, if they decide to proceed with limited emergency care.