Abscesses and cold sores represent two common oral-facial complaints. Both result from infections: bacteria cause abscesses, the herpes simplex virus causes cold sores. Doctors and dentists rely on history and physical examination to tell whether a patient has an abscess or a cold sore. Laboratory tests can confirm the diagnosis and identify the specific species of bacteria or virus, if necessary.
In the 2008 edition of “Fitzpatrick’s Dermatology in General Medicine,” University of Massachusetts Professor of Dermatology Amit Garg, M.D. says that an abscess is a localized collection of pus below the surface layer of skin, where the pus itself is usually not seen. A cold sore begins as a blister—a collection of clear fluid that becomes cloudy and puslike after a few days. Unlike an abscess, the fluid is clearly visible. Both an abscess and a cold sore are surrounded by red, swollen skin.
Garg says that an abscess usually develops over the course of a few days or weeks, when the immune system creates a wall between infected and healthy tissue as a means of controlling its spread. In the June 9, 2008 issue of Archives of Internal Medicine, Northeastern Ohio University dermatologist Christina Cernik, M.D. says that a cold sore develops over the course of a few hours. In fact, says Cernik, the blister actually develops from a solid bump that fills with fluid so quickly that patients rarely notice the bump phase.
Cernik says that, without treatment, cold sores usually resolve in 10 to 14 days. With treatment, cold sores resolve sooner—sometimes as soon as five days, depending on how quickly the patient starts treatment. Cold sores last longer during the first outbreak, compared to recurrent outbreaks. Abscesses, by contrast, persist indefinitely without treatment.
According to Cernik, 90 percent of cold sores develop on borders of the lips, called the vermillion. Five percent occur on facial skin, especially the chin, the skin between the lips and the nose and the nose itself. Five percent occur inside the mouth, especially on the roof of the mouth and less often on the back of the throat, the lining of the cheeks, the gums and the tongue. An abscess can develop anywhere and is often preceded by a history of tooth cavities or injuries that allows bacteria to gain entry to the soft tissue.
Both abscesses and cold sores produce pain. Cold sores also cause itching, especially as they start to heal. Some people with abscesses and cold sores report flulike symptoms such as fever, fatigue, headache, sore throat or a generalized sense of malaise.
Cold sores resolve without treatment. However, patients who experience severe symptoms or recurrent episodes benefit from topical or oral antiviral drugs which speed healing. An abscess requires surgical drainage of the pus, followed by antibiotics to clear the infection. In many cases, a doctor sends a sample of the drained pus to the laboratory to confirm that it will respond to the selected antibiotics.