ASK THE DOCTOR: Cold sores and canker sores;
Different problems and different treatments
By DR. JIM MITTERANDOQ What is the difference between cold sores and canker sores? I get sores on my lips several times a year that are quite painful and unattractive. What can I do?
A Your description fits cold sores, (fever blisters), which are different from canker sores.
Cold sores are usually on the lips, but can also develop on cheeks and nose. Certain strains of the herpes virus cause cold sores. Herpes simplex virus type 1 usually causes cold sores; herpes simplex virus type 2 usually causes genital herpes.
Once you’ve had an episode of cold sores, the herpes virus lies dormant in the nerves of your face. It is reactivated by sunburn, a recent viral illness (cold or flu), menstrual period or stress.
Sometimes the herpes virus can affect the cornea (the clear window) of the eye, which can threaten vision and requires immediate medical attention and treatment. If you have an outbreak of cold sores and develop eye pain or blurry vision, call your doctor. People who have compromised immune systems because of cancer treatment or AIDS can have more serious problems with the herpes virus.
Prevention of cold sores
- Cold sores are very contagious. When you have an outbreak, don’t kiss others or share food, drink. The virus can be spread as long as there are moist secretions from your blisters.
- The virus can spread during an outbreak, so be careful about touching other parts of your body; eyes and genitals are particularly susceptible.
- Use sunblock or zinc oxide ointment on your lips before prolonged exposure to the sun - during both the winter and the summer - to help prevent cold sores
Self-care of cold sores
Cold sores generally last about seven to 10 days. They develop into painful blisters that turn to scabs. In the meantime, the following steps may provide relief:
Over-the-counter treatments: Use over-the-counter pain relievers, such as acetaminophen (Tylenol) or ibuprofen (Motrin, Advil). Also, avoid squeezing or picking at any blister. Also try ice to ease the pain. Over-the-counter creams provide temporary comfort by numbing the blisters, but do not speed healing. Acidophilus pills may be helpful in treating cold sores. L-lysine is an amino acid widely advertised to treat cold sores. Conflicting medical studies raise the question whether it is truly effective. Some people have told me that this medication helps them.
Prescription treatments: Antiviral pills - acyclovir (Zovirax), famciclovir, (Famvir), and valacyclovir (Valtrex) - can abort an outbreak and help recurrent breakouts. These should be taken within in the first 24 hours of feeling the tingling or discomfort - before the blisters erupt. The duration of the outbreak can shorten by a day or two.
Antiviral creams - Zovirax, Denavir - are not as effective as the pills; studies show the creams only reduce the duration of an outbreak by a half-day. I do know a few people who tell me the creams help, but I find the pills to be a much better treatment. In addition, acyclovir pills cost half the price of the creams.
Canker sores
Also known as aphthous ulcers, canker sores are more difficult to treat since the cause is unknown. Canker sores are painful, tiny ulcers inside the mouth, not on the lips like herpes. Cold sores, on the other hand, generally do not occur inside the mouth. Unlike cold sores, canker sores are not contagious. They are caused by stress, illness, sleep deprivation and some foods. The sores last about five to 10 days.
There is no cure; treatments try to alleviate symptoms or shorten duration. There is simply no great remedy and no one right treatment for everyone. If one remedy does not work, then try another.
Prevention of canker sores
- Some people find avoiding certain foods - citrus fruits, tomatoes and some nuts, may reduce canker sores.
- Trauma, such as biting the inside of your mouth, or vigorous tooth brushing may exacerbate the problem
- To decrease canker sores change to a ‘‘SLS (sodium laurylsulfate)-free’’ toothpaste, such as Rembrandt, some people say.
Treatment of canker sores
For pain relief in a prescription, try 2 percent viscous lidocaine - applied with a cotton swab (Q-tip) several times daily.
The prescription, steroid ointment, Kenalog (triamcinolone) in Orabase, also may provide some relief. Tetracycline syrup or tetracycline capsules dissolved in water may also help some people.
The only FDA-approved treatment for canker sores is an anti-inflammatory ointment, called Aphthasol, which is only modestly effective.
Over-the-counter benzocaine preparations (Anbesol and Oragel) may also be used. Over-the-counter ointments such as Orabase or Zilactin-B, coat the ulcers and may provide some protection and comfort.
If you use an ointment to treat a canker sore, you should, first, dry the sore with a tissue. Next, put a small amount of medicine on a cotton swab and apply to the sore. Don’t eat or drink for 30 minutes to prevent the medicine from being washed away.
Sucking on zinc lozenges, taking vitamin C or vitamin B complex, using a sage-and-chamomile mouthwash or taking a lysine supplement, are remedies used by some. No good scientific studies support these.
For symptomatic relief: Mix equal amounts of Milk of Magnesia and Benadryl Allergy liquid. Swish a teaspoonful in your mouth for about one minute and then spit it out. If you do this every four to six hours, your canker sores may hurt less.
Dr. Jim Mitterando is a family doctor at Cohasset Family Practice and a staff member at South Shore Hospital in Weymouth.
Readers should send questions to: Ask the Doctor, The Patriot Ledger, P.O. Box 699159, Quincy, MA. 02269-9159, or by E-mail to his attention at features@ledger.com.
Questions of general interest will be answered in this column. The information in this column is not intended to diagnose individual conditions, and individual replies are not possible. Readers should see their own doctors about specific problems.
Copyright 2003 The Patriot Ledger
Transmitted Tuesday, April 08, 2003