A high proportion of infants and young children suffer from primary herpes virus infection of the lips and oral mucosa. Many of these infections are subclinical and the patient presents no symptoms. Such subclinical infections can lead to a resistance to future infection. However, the virus can remain latent in the lips and in later life can give rise to cold sores, a condition known as recurrent herpes. Such recurrences appear spontaneously or may be precipitated by trauma (e.g. accidental cut of lip when shaving), sunlight and menstruation.
There is also a suggestion that stress can lead to these cold sores, though this has not been proven. Cold sores begin with a burning sensation on the affected area of the lips which is usually followed by the development of a painful blister (vesicles) which eventually become ulcers (pustules) and then heal gradually in 7-14 days. Cold sores are contagious and strict hygiene measures should be adopted when a family member is infected.
Prevention is problematical though the use of sun barrier creams will help reduce attacks in those holidaying in the sun. Also a well established product on the market (contains 5% w/w acyclovir), if applied during the early burning phase, has been shown to be very effective in reducing the length of the blister stage and can get rid of the pustule stage.
Dental Health Foundation Ireland