Cold Sores and Canker Sores?What Is the Difference?

Cold sores and canker sores are 2of the most unwelcome oralproblems patients can develop.Whereas the 2 conditions occur on orin the mouth and patients often confusethem, their causes are very different.These common lesions may notbe dangerous, but they are painful andunsightly, so pharmacists are likely tofield plenty of questions from patientsdesperate for treatment.

Cold Sores

Brad Rodd, DDS, professor at theUniversity of Alabama in Birmingham,estimates that 20% to 30% of peoplesuffer from recurring cold sores (orfever blisters), which are caused by theherpes simplex type 1 virus. Like itscousin the herpes simplex type 2 virus,which causes genital lesions, the virusthat causes cold sores is contagious.

"Most people come into contactwith the virus when they are children,"Dr. Rodd said. "In some cases,the virus sets up shop in a nerve ganglionin the body. While it doesn'taffect the nerve, it can exist in thenerve forever and can erupt to the surfacefrom time to time when a patienthas a cold or fever, is experiencingstress, is exposed to the sun, or whenthere's trauma or stress to the area,such as a patient might experience ona visit to the dentist."

When conditions are ripe, the viruscan come "marching out," said Dr.Rodd, resulting in a painful andunsightly eruption on the skin. Lesionsfirst become visible as small, redpapules or fluid-containing vesiclesabout 1 to 3 mm in diameter. Manylesions can coalesce into a single largerlesion, and, as the sore matures, a crustforms over the vesicles that have erupted.Cold sores usually are self-limitingand generally heal without scarring in7 to 10 days. "Cold sores aren't somuch painful as they are embarrassing,"he said.

Unfortunately, there is not muchthat patients can do to prevent thevirus, and, once contracted, the viruscannot be eradicated. "These virusesare hidden deeply in the body so thatdrugs can't reach them, so there's reallyno cure," Dr. Rodd said.

The promising news, according toDr. Rodd, is that, if patients treat theoutbreak quickly enough, they canbeat the sore back before it gets too"comfortable" on the skin's surface."Patients should treat the area as soonas possible?the very second they feelsomething coming on," he said.Because lesions tend to form in thesame spot, patients usually can tellwhen an eruption is about to occur,due to tingling, burning, itching, ornumbness in the area.

Dr. Rodd recommends either Abrevaor the Zilactin line of oral health careproducts, OTC products that he believescan effectively inhibit the developmentof cold sores. The active ingredientsin these products (doconasol inAbreva and benzyl alcohol in theZilactin products) suppress sensoryreceptors and offer relief from pain anditching. Anbesol, Blistex, Campho-Phenique, Carmex, Orabase, and Orajelare other products recommendedby pharmacists for treating cold sores.

Dr. Rodd cautions that highly astringentproducts containing ingredientssuch as tannic acid and zinc sulfate arenot safe or effective treatments for coldsores and should be avoided.

Pharmacists also can recommendthat patients keep the area moist as thelesion begins to form a crust. If thelesion cracks, it may be more susceptibleto secondary bacterial infection,which can delay healing. Commonskin protectants, such as petrolatumand cocoa butter, can be used to keepthe area moist.

Patients who have recurring, but notdebilitating, cold sores may want toconsider a more systemic approach."There are a lot of medicines that cantreat symptoms, but it may be a goodidea to try to prevent cold soreepisodes," said Tony Welder, owner ofDakota Pharmacy in Bismarck, ND."There are many natural medicinesthat can strengthen the immune system.Many people benefit from lysineor balanced amino acids as a preventative,besides strengthening the immunesystem with essential fatty acidsand vitamin C. The treatment of coldand canker sores with probiotics orenterobiotics may seem strange, but itworks." Many pharmacists recommendHerpecin-L, a product that containslysine, an amino acid thought tointerfere with the ability of the herpesvirus to absorb arginine (necessary forits reproduction).

Canker Sores

In addition, Welder suggests a boostto the immune system as a preventionagainst mouth sores or canker sores.Also referred to as recurrent aphthousulcers, canker sores are found exclusivelyinside the mouth. They canrange in severity from ones that occuroccasionally and are self-healing tovery large and numerous ulcers thatcan be difficult to heal.

The sores usually form on thetongue, the floor of the mouth, thesoft palate, or the inside lining of thelips and cheeks. Most lesions last 7 to14 days and heal spontaneously withoutscarring.

Whereas cold sores have a knowncause, the cause of mouth soresremains elusive. "No one knows whythey occur," Dr. Rodd said. "We knowit's not an infection. It's probablysome sort of localized inflammationproblem. There are fairly complexinteractions going on at the ulcerlevel, but we really don't know muchmore."

"When mouth ulcers are large,numerous, and difficult to heal, theycan be debilitating for a patient," saidDr. Rodd. "When the condition is thatserious, the patient should really bereferred to a physician, since in rarecases severe mouth ulcers can be asymptom of a bigger problem, such asCrohn's disease or Behcet's disease."Pharmacists can refer patients withpersistent mouth sores to an oralpathologist. "These specialists arefound through medical centers or dentalschools," he said.

For milder cases (occasional lesions),treatment is focused on controllingdiscomfort and protecting the soresfrom irritation from food or routineoral hygiene. "The biggest problem isthat these lesions hurt, and OTC products,while they don't actually heal, doa good job of providing pain relief," Dr.Rodd said.

Topical products containing benzocaine?such as Anbesol, Orabase, orZilactin-B?often are recommended.Dr. Rodd recommends a gel formulation,because a gel provides a polymermembrane over the ulcer, helping tocreate a barrier and reduce pain. Otherproducts on the market include Campho-Phenique, Carmex, Gly-Oxide,Kanka, and Tanac. Dr. Rodd cautionsthat patients with a history of hypersensitivityto benzocaine should notuse benzocaine-containing products.

Products that release nascent oxygenalso can be used to provide temporaryrelief but should not be used for morethan 7 days. Saline rinses can providesome soothing relief to the area.

Ms. Sax is a freelance writer based inRidgewood, NJ.