The herpes simplex virus is known for its damaging effects in the oral and genital regions. Known to be a facilitator of cold sores, this virus exerts its primary infection in children between 6 months to 6 years of age. Signs of the virus' clinical manifestations often go unreported due to it being confused with other lesions and clinical conditions.

How does the cold sore develop?

Once the herpes simplex virus enters the body it clings on to an area of confluence of nerves called a ganglion. Most commonly, the virus stays dormant in a sensory ganglion of the orofacial region. The dormancy phase will exist unless and until the virus is triggered by an external stimuli like fever, UV light exposure, stress, common cold, fatigue, trauma, immunosuppression, menstruation, oral and facial surgery, chemotherapy, etc. The recurrence of the herpes infection most commonly affects the gingiva and lips in the orofacial region.

Once the herpes simplex virus is reactivated, it follows two routes. It is either suppressed by the body's defense mechanism to the extent that the clinical symptoms are barely seen, or it can kick in a prodromal phase of fatigue, malaise and fever, before the lesion enters its active stage. In this active stage, there will be a formation of an initial papule, which converts into an infectious fluid-filled lesion. This lesion usually takes around two weeks to heal.

How does a cold sore affect dental appointments and dental procedures?

A dental procedure in a patient with an active lesion puts both the patient and the operator at risk. The dental surgeon should defer the procedure for after two weeks if there is no need for an emergency treatment. If an emergency treatment is warranted, then in order to avoid any occupational hazard, the dental surgeon should wear full sleeves lab coats, face shield, gloves and all the necessary personal protective equipment which can minimise the transmission of the virus.

A patient with a cold sore who requires a tooth extraction procedure puts both himself/herself at a risk of infection and also the dental surgeon from getting a herpetic infection. Tooth extraction is an invasive procedure and greater the invasiveness of the procedure, more is the risk of a herpetic infection. In the patient, the stretching of the tissues, deposition of anesthetic agents near the nerve complexes, bleeding due to rupture of the socket vessels are many risk factors of getting a herpetic infection. The recurrent lesions affect the soft tissues as the virus travels down from the ganglion.

The dentist too would be at a risk of acquiring the virus should he or she opt to extract a tooth in the case of an active herpetic lesion. Herpetic whitlow, is a form of lesion that affects the thumbs and is an occupational hazard to dentists who operate in a patient with an active lesion. Ophthalmic keratitis, which affects the cornea of the eye is the second most common occupational hazard in this respect.

If a tooth extraction is performed in a case on active lesion, then the activation of the virus can retard the healing of the extraction socket. This can also lead to a painful condition called dry socket. Another complication can arise in case there is an accidental injury or wound during the insertion of needle while administering anesthesia. This can cause neuropathy of the facial region that is in proximity with the injured nerve. Going a step back, even the stress, fear and anxiety induced in the patient when he or she is scheduled for dental extraction is one of the triggering factors for activation of the virus.

When compared to other dental procedures like scaling and restoration, a patient carries the maximum risk of getting a herpetic lesion if he or she is scheduled for extraction. In order to minimise the risk of herpetic infection, the patient can be put on an antiviral regime of Valacyovir or acyclovir to minimise the chance of infection. This should be done within 72 hours of the eruption of the lesion. Additionally, topical anesthetics, anti-inflammatory agents and analgesics can further help in control of the spread of the lesion.

Tooth or teeth extractions, if possible should be deferred till the healing stage of the herpetic lesion is reached. Precautionary measures as mentioned above must be followed in cases when the treatment needs to be carried out immediately and mandatorily.