Herpes viruses typically infect the oral or genital mucosa. When herpes affects the mouth, it causes the typical "cold sores," which are painful sores or blisters that form on the lips, mouth, or gums. Prior to the development of the blisters, there may be a prodrome (early symptoms indicating onset of a particular disease) consisting of an itching, burning, or tingling sensation in the affected area. The virus remains dormant in the nervous system throughout life, and this is the reason that cold sores often recur in the same location.
Herpes “triggers” (determining exactly what leads to an outbreak) are highly individual, but with time, many people learn to recognize, and sometimes avoid, factors that seem to reactivate HSV in their own bodies. Illness, poor diet, emotional or physical stress, friction in the genital area, prolonged exposure to ultraviolet light (commonly for oral herpes, such as a beach trip or skiing weekend), surgical trauma, and steroidal medication (such as asthma treatment) may trigger a herpes outbreak.
"When you are having an outbreak of oral herpes, symptoms usually start with a burning, itching or tingling sensation on your lips," Michael says. "This will intensify until a small rash, and then blisters, appear. These sores are commonly called 'cold sores'. The blisters are usually filled with a clear or slightly yellow liquid. Over a short time, these blisters will burst leaving a painful, raw area. These will then dry and scab over. The scabs will generally fall off after a week or two, leaving fresh clear skin beneath."