Your doctor can usually diagnose cold sores just by looking at them. To confirm the diagnosis, your doctor might take a sample from the blister for testing in a laboratory.
Cold sores generally clear up without treatment in two to four weeks. Several types of prescription antiviral medications may speed the healing process. Examples include:
- .Acyclovir (Zovirax)
- Valacyclovir (Valtrex)
- Penciclovir (Denavir)
Some of these products are packaged as pills to be swallowed. Others are creams to be applied to the sores several times a day. In general, the pills work better than the creams. For very severe infections, some antiviral drugs can be given with an injection.
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Lifestyle and home remedies
The over-the-counter cold sore ointment docosanol (Abreva) may shorten the healing time of a cold sore. At the first sign of symptoms, apply it to the affected skin as directed on the package. Use a cotton-tipped swab to put medicine on a cold sore. This helps prevent the spread of the sores to other parts of your body.
To ease the discomfort of a cold sore:
- Try other cold sore remedies. Some over-the-counter preparations contain a drying agent, such as alcohol, that may speed healing.
- Use lip balms and cream. Protect your lips from the sun with a zinc oxide cream or lip balm with sunblock. If your lips become dry, apply a moisturizing cream.
- Apply a compress. A cold, damp cloth may reduce redness, help remove crusting and promote healing. Or try a warm compress to the blisters to ease pain.
- Rest and try pain relievers. Take over-the-counter pain relievers if you have a fever or the cold sore is painful. Creams with lidocaine or benzocaine may offer some pain relief.
Although study results have been mixed, alternative medicine treatments for cold sores include:
- Lysine. An amino acid, lysine is available as an oral supplement and as a cream.
- Rhubarb and sage. A cream combining rhubarb and sage may be about as effective as acyclovir (Zovirax) cream.
- Stress reduction. If your cold sores are triggered by stress, you might want to try relaxation techniques, such as lemon balm extract, deep-breathing exercises and meditation.
- Propolis. Also known as synthetic beeswax, this is available as a 3% ointment. When applied early and often, it might shorten the duration of the breakout.
Preparing for your appointment
Cold sores generally clear up without treatment in two to four weeks. Make an appointment with your family doctor if your cold sores:
- Are lasting or severe
- Return often
- Are accompanied by eye discomfort
What you can do
Before your appointment, you may want to list answers to the following questions:
- Have you ever had these symptoms before?
- Do you have a history of skin problems?
- What medications and supplements do you take regularly?
Below are some basic questions to ask your doctor about cold sores.
- Do I have a cold sore?
- What treatment approach do you recommend, if any?
- What self-care steps can I follow to ease my symptoms?
- Am I contagious? For how long?
- How do I reduce the risk of spreading this condition to others?
- How soon do you expect my symptoms will improve?
- Am I at risk of complications from this condition?
- Can I do anything to help prevent a recurrence?
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to talk about in-depth. Your doctor may ask:
- Could you sense a cold sore coming before the sore became visible?
- Do your symptoms include eye irritation?
- Have you noticed if anything in particular seems to trigger your symptoms?
- Have you been treated for cold sores in the past? If so, what treatment was most effective?
- Have you recently experienced significant stress or major life changes?
- Are you pregnant?
- Does your work or home life bring you into contact with infants or with people who have major illness?
June 17, 2020
- AskMayoExpert. Cold sores (herpes simplex infection). Mayo Clinic; 2019.
- Dinulos JGH. Warts, herpes simplex, and other viral infections. In: Habif's Clinical Dermatology. 7th ed. Elsevier; 2021. https://www.clinicalkey.com. Accessed April 7, 2020.
- Herpes simplex. American Academy of Dermatology. https://www.aad.org/public/diseases/a-z/herpes-simplex-overview. Accessed April 7, 2020.
- Ferri FF, et al., eds. Herpes simplex. In: Ferri's Fast Facts in Dermatology: A Practical Guide to Skin Diseases and Disorders. 2nd ed. Elsevier; 2019. https://www.clinicalkey.com. Accessed April 7, 2020.
- Kermott CA, et al., eds. Canker sores. In: Mayo Clinic Book of Home Remedies. 2nd ed. Time; 2017.
- Kermott CA, et al., eds. Cold sores. In: Mayo Clinic Book of Home Remedies. 2nd ed. Time; 2017.
- Gibson LE (expert opinion). Mayo Clinic. April 6, 2015.
- Lemon balm. Natural Medicines. https://naturalmedicines.therapeuticresearch.com/. Accessed April 8, 2020.
- Lysine. Natural Medicines. https://naturalmedicines.therapeuticresearch.com/. Accessed April 8, 2020.
- Rhubarb. Natural Medicines. https://naturalmedicines.therapeuticresearch.com/. Accessed April 8, 2020.
- Propolis. Natural Medicines. https://naturalmedicines.therapeuticresearch.com/. Accessed April 8, 2020.
- Bauer BA, ed. Making wellness the focus of care. In: Mayo Clinic Guide to Integrative Medicine. Time; 2017.
- Klein RS. Treatment of herpes simplex virus type 1 infection in immunocompetent patients. https://www.uptodate.com/contents/search. Accessed April 8, 2020.
- Hargitai IA. Painful oral lesions. Dental Clinics of North America. 2018; doi.10.1016/j.cden.2018.06.002.