Oral herpes, an infection caused by the herpes simplex virus, is estimated to be present in 50 to 80 percent of the American adult population. 20 percent, over 50 million people, are infected with genital herpes, also caused by the herpes simplex virus, and the majority of these cases may be unaware they even have it. Studies show that more than 500,000 Americans are diagnosed with genital herpes each year, and the largest increase is occurring in young teens.

Herpes zoster, colloquially known as shingles, is the reactivation of varicella zoster virus, leading to a crop of painful blisters over the area of a dermatome. It occurs very rarely in children and adults, but its incidence is high in the elderly (over 60), as well as in any age group of immune compromised patients.