Herpes labialis (cold sore, fever blister) is a commonly occurring ailment. Its average incidence is 1.6 per 1000 patients per year and its prevalence is 2.5 per 1000 patients per year. 1 Approximately one-third of all infected patients suffer relapses. 2 Herpes labialis is a rash of the skin and mucous membranes (in particular, the lips) and …