"Fitzpatrick's Dermatology in General Medicine" explains that more than 90 percent of people eventually acquire the herpes simplex virus that causes cold sores. About 60 percent experience symptoms so mild that they go unrecognized as cold sores. The remaining 30 percent experience the lesions classically referred to as cold sores. Key features can help patients distinguish between herpes and causes of cold sores other than herpes.
The National Institute of Dental and Craniofacial Research says that more than 100 strains of human papillomavirus, the virus that causes most warts, have been identified as of 2010 just on the mouth and lips. The condition usually occurs in children who transfer the virus to the mouth and lips when they chew or suck on warts on their hands. Adults with oral warts usually acquire them through oral intercourse with someone who has genital or anal warts. Some infections are spread by people who are themselves asymptomatic. Cold sores typically resolve spontaneously within 10 to 14 days, while warts take 1 or 2 years, according to the National Institutes of Dental and Craniofacial Research.
The Academy of General Dentistry says that location is the key to distinguishing between apthous ulcers, also known as canker sores, and cold sores. Apthous ulcer occur exclusively inside the mouth. By contrast, according to the June 9, 2008 edition of "Archives of Internal Medicine," just 5 percent of cold sores develop inside the mouth. The American Dental Association says the cause of apthous ulcers remains elusive, with evidence implicating immune system problems, viruses and bacterial infections. Like cold sores, apthous ulcers usually resolve spontaneously within 1 to 2 weeks.
The 2010 edition of "Current Diagnosis and Medical Treatment" explains that a lesser known name for the varicella-zoster virus that causes chicken pox is human herpes virus 3. Herpes simplex viruses 1 and 2, the viruses commonly referred to as "herpes," represent the first two members of the family. Like herpes, varicella-zoster produces blisters and sores that usually resolve spontaneously within 1 to 2 weeks. Like herpes, the lesions often appear first on the face and inside the mouth. Unlike herpes, they soon spread to the back, abdomen, arms and legs -- sites where cold sores are rarely seen. Also unlike herpes, chicken pox almost never strikes more than once. According to the National Institute of Dental and Craniofacial Research, between 20 and 40 percent of people with cold sores experience recurrent outbreaks.