Triggers for Cold Sores

An estimated 80 percent of Americans carry the virus that causes cold sores, with 62 percent infected by the time they reach adolescence, according to MedlinePlus and the University of Maryland Medical Center. The virus can lie dormant until a trigger activates an outbreak, causing fluid-filled blisters to appear on or around your lips. Triggers are different for each person, but knowing how to identify and avoid them can help prevent a recurrence.

Causes and Symptoms

• The herpes simplex type 1 virus is the most common cause of cold sores. You may first get a cold sore after kissing someone infected with the virus, or from sharing towels, razors and eating utensils. Symptoms vary for each person but may include an itching or tingling sensation one to two days before the appearance of a cold sore and blistering on or near your lips. After the blisters break open and ooze, a reddish sore appears. It later scabs and eventually heals without scarring. While less common, cold sores can also appear on your nostrils, chin or fingers or inside your mouth.

Triggers

• Nearly one-third of people infected with the herpes simplex type 1 virus have a recurrence of the condition, a study published in the December 2008 issue of "Canadian Family Physician" found. Once you have had your first cold sore, the virus may lie dormant in your skin's nerve cells until one of many factors triggers a recurrence. These triggers include a cold or infection, emotional stress, sadness or upset, menstruation, extensive exposure to sunlight, injury to the affected area, digestive problems, traveler's diarrhea and fatigue. Often the virus attacks the body when your immune system is low or fighting an infection or illness.

Research

• A case report by Lara El Hayderi and colleagues in a January 2011 edition of the journal "Medicina Oral, Patología Oral y Cirugía Bucal," found seven people who had dental surgery --- incisor or molar extraction, or a filling, had a cold sore outbreak two to three days after surgery. Five patients experienced more severe symptoms than usual and none had previously experienced a cold sore outbreak after surgery. The findings suggest dental surgery triggers a cold sore recurrence that is more severe in people with a history of cold sores.

Avoiding Triggers

• The best way to avoid the triggers that may cause a cold sore outbreak is to maintain a healthy diet and lifestyle. Exercise, sleep and avoiding stress are important to prevent a recurrence of the virus. Apply sunscreen to your lips when exposed to the sun and keep your lips moisturized to avoid chapped lips, which may also cause the condition. Research has also found ingesting 1 g to 3 g of lysine per day, found in foods such as chicken, potatoes or eggs, or from lysine supplements, helps reduce the number and duration of outbreaks, the University of Maryland Medical Center notes.

Treatment

• While there is no cure for cold sores, over-the-counter medications can help treat the condition and prevent outbreaks. Topical treatments such as lidocaine and benzocaine, can help relieve pain and symptoms, while antiviral medication such as acyclovir, famciclovir and valacyclovir can reduce the duration and recurrence of cold sores when the first symptoms appear. These oral antiviral medications can lower the risk of another outbreak by up to 80 percent, according to the University of Maryland Medical Center.