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Introduction
Cold sores, also known as fever blisters or oral herpes, are small, painful blisters which usually appear on or around the lips. Cold sores are caused by the herpes simplex virus (HSV), which is highly contagious and can be easily spread through close contact with an infected person. While there is no cure for HSV, there are treatments to help manage symptoms, speed up healing, and reduce the frequency of outbreaks.
In this article, we'll explore what cold sores are, their common causes and triggers, effective medical treatments, home remedies for symptom relief, and when it's a good idea to consult a healthcare provider.
What Are Cold Sores?
Cold sores are small, fluid-filled blisters that usually form on the lips or around the mouth. They are caused by the herpes simplex virus type 1 (HSV-1), which is a highly contagious virus that infects the majority of the population. Once a person catches HSV-1, the virus stays dormant in their nerve cells and can reactivate from time to time, causing cold sore outbreaks.
A typical cold sore outbreak progresses through several stages:
- Prodrome stage: A tingling, itching, or burning sensation may be felt around the mouth or lips 24-48 hours before a cold sore forms.
- Blister stage: Small, painful, fluid-filled blisters appear, usually in clusters. The blisters can appear on the lips, nose, cheeks, or chin.
- Weeping stage: The blisters burst open and ooze clear or yellowish fluid, forming shallow ulcers. This stage is highly contagious.
- Crusting stage: The ulcers dry out and form a yellow or brown crust or scab over the sores.
- Healing stage: The scabs fall off, revealing new skin underneath. The cold sore outbreak typically resolves within 7-10 days without treatment. 1,2
Cold sores are highly contagious and can be spread through direct contact with the sores, saliva, or other bodily fluids of an infected person. The virus can also be transmitted even when there are no sores, as you can still spread the virus without symptoms. It's important to avoid close contact with someone who has an active cold sore outbreak to prevent infection. 5
Cold sores are very common, with about 3.7 billion people under the age of 50 worldwide infected with HSV-1. In the United States, approximately 50-80% of adults carry the virus. Not everyone with HSV-1 will get recurrent cold sores. 14,33
Cold sores can have an impact on your quality of life because of physical discomfort, emotional distress, and social stigma. The painful blisters can make eating, drinking, and speaking difficult, and the appearance of cold sores can cause you to feel self-conscious and embarrassed. Recurrent outbreaks can also disrupt daily life, affecting work, school, and personal relationships. Medical treatments and self-care can help you manage cold sores.
Common Causes and Triggers of Cold Sores
Cold sores are caused by the herpes simplex virus type 1 (HSV-1), a highly contagious virus that is spread through direct contact with an infected person's skin, saliva, or other bodily fluids. Once someone contracts HSV-1, the virus remains dormant in their nerve cells and can reactivate, causing recurrent cold sore outbreaks.
Several factors can trigger a cold sore outbreak, including:
- Stress and fatigue: Both physical and emotional stress can weaken the immune system and trigger a cold sore outbreak. Stress-related hormonal changes may also contribute to reactivation.
- Illness and weakened immune system: Illnesses such as the common cold or flu can weaken the immune system and make you more susceptible to a cold sore outbreak. People with chronic health conditions or compromised immune systems, such as those with HIV/AIDS or undergoing cancer treatment, are at a higher risk of developing severe and recurrent cold sores.
- Hormonal changes: Changes in hormones, such as during menstruation, pregnancy, or menopause, can trigger cold sore outbreaks in some people. These hormonal shifts can affect the immune system's ability to suppress the virus.
- Sun and wind exposure: Prolonged exposure to sunlight or strong winds can damage the skin and trigger a cold sore outbreak. UV radiation can weaken the immune system locally and reactivate the virus.
- Skin injuries: Trauma to the skin, such as cuts, scrapes, or dental procedures, can trigger a cold sore outbreak in the affected area. 1,2,3,6,11,12,13
Triggers vary from person to person, and some people may get cold sores without any apparent trigger. Identifying personal triggers can help people with HSV-1 prevent and reduce the frequency and severity of outbreaks.
To minimize the risk of cold sore outbreaks, you can:
- Practice stress management techniques, such as meditation, deep breathing, or regular exercise
- Maintain a balanced diet and get enough sleep to support a healthy immune system
- Use sunscreen or lip balm with SPF protection to prevent sun damage
- Avoid excessive alcohol consumption and smoking, which can weaken the immune system
- Take steps to prevent the spread of infection during an active outbreak, such as avoiding close contact and practicing good hygiene
Effective Treatments for Cold Sores
While there is no cure for the herpes simplex virus that causes cold sores, there are effective treatments that can help manage symptoms, speed up healing, and lower the frequency of outbreaks.
Antiviral medications
Prescription antiviral medications are the most effective treatment for cold sores. These drugs prevent the herpes simplex virus from spreading within the body. The most common antiviral medications for cold sores are:
- Acyclovir (Zovirax): This drug is available as an oral tablet, capsule, or suspension, as well as a topical cream. Oral acyclovir is most effective when taken at the first sign of a cold sore outbreak.
- Valacyclovir (Valtrex): This is a prodrug of acyclovir, meaning it is converted into acyclovir within the body. Valacyclovir has a longer half-life which means you need to take it less often than acyclovir. A single-day, high-dose regimen of 2 grams twice daily has been shown to be highly effective in lowering the duration and severity of cold sore outbreaks.
- Famciclovir (Famvir): This drug is also available as an oral tablet and is most effective when taken at the first sign of a cold sore.
- Penciclovir (Denavir): This topical cream can be applied directly to the cold sore. It is most effective when used at the earliest stage of an outbreak, such as during the prodrome or tingling phase. 16,17,19
Over-the-counter topical creams containing docosanol (Abreva) can also help reduce the duration and severity of cold sore outbreaks when applied at the first sign of symptoms.
For people with frequent or severe outbreaks, healthcare providers may recommend taking an antiviral medication daily to prevent future outbreaks. 14,17
Emerging and alternative treatments
Recent research has explored various alternative therapies for treating cold sores:
- Kanuka honey: A study found that medical-grade kanuka honey from New Zealand was as effective as acyclovir cream in reducing the duration and severity of cold sore outbreaks. The honey's antiviral and wound-healing properties make it a natural treatment option. 22
- Dietary supplements: Certain supplements, such as lysine, vitamin C, and zinc, may help support the immune system and reduce the frequency and severity of cold sore outbreaks. However, the effectiveness is still being studied, and you should consult a healthcare provider before starting any new supplements.
While these alternative treatments are promising, it is important to speak with a healthcare provider before using them, as they may interact with other medications or cause side effects in some people.
Home Remedies and Self-Care for Cold Sores
In addition to medical treatments, several home remedies and self-care measures can help manage cold sore symptoms, promote healing, and prevent future outbreaks.
Lifestyle changes to prevent outbreaks
Making certain lifestyle changes can help reduce the frequency and severity of cold sore outbreaks:
- Stress management: Stress is a common trigger for cold sores. Practicing stress-reducing activities such as meditation, deep breathing, yoga, or regular exercise can help strengthen the immune system and prevent outbreaks.
- Healthy diet: Eating a balanced diet of fruits, vegetables, whole grains, and lean proteins can support a healthy immune system. Certain foods, such as those high in lysine (e.g., fish, chicken, and beans), may help suppress the herpes simplex virus.
- Avoiding triggers: Identifying and avoiding personal triggers can help prevent cold sore outbreaks. 15,18,20,21
Relieving discomfort of active sores
When a cold sore outbreak occurs, some home remedies can help alleviate pain, itching, and discomfort:
- Cold compresses: Applying a cold, damp cloth or ice pack to the affected area for 5-10 minutes at a time can help numb pain and reduce inflammation.
- Aloe vera gel: Applying pure aloe vera gel to the cold sore may feel soothing and can promote healing. Some studies suggest that aloe vera has antiviral and anti-inflammatory properties.
- Petroleum jelly: Applying a thin layer of petroleum jelly (vaseline) to the cold sore can help keep the area moist, prevent cracking and drying, and promote healing. It also can help protect the sore from bacteria.
- Pain relievers: Over-the-counter pain relievers such as acetaminophen or ibuprofen can help relieve pain and reduce inflammation. 7,8,9,10
Preventing spread of infection
As cold sores are highly contagious, it is important to not spread the virus to others or to other parts of the body:
- Avoid touching the sore: Touching or picking at a cold sore can spread the virus to other parts of the body or to other people. If you touch the sore, wash your hands thoroughly with soap and water afterward.
- Don't share personal items: Avoid sharing items that come into contact with the mouth or cold sore, such as utensils, cups, towels, or lip balms.
- Practice good hygiene: Wash your hands often, especially before touching your face or preparing food. Keep the area clean and dry to promote healing and prevent bacterial infections. 2,3,4,5
These home remedies can be used to help support your cold sore management plan and reduce the discomfort and duration of outbreaks as well as minimize the risk of spreading the infection to others.
When To See a Healthcare Provider for Cold Sores
While cold sores typically heal on their own within 7-10 days, there are certain situations where you should visit a healthcare provider for proper diagnosis and treatment.
Signs of a severe outbreak
Seek medical attention if you experience any of the following symptoms during a cold sore outbreak:
- High fever: A fever above 101°F (38.3°C) with a cold sore may indicate a more severe infection.
- Difficulty swallowing or breathing: If a cold sore in the mouth or throat makes it difficult to swallow or breathe, seek immediate medical care.
- Spread of sores: If the cold sores spread to other parts of the body, such as the eyes or genitals, consult a healthcare provider to prevent serious complications.
- Duration: Persistent or large cold sores that do not heal within 2 weeks could be a sign of a more serious underlying condition or a complication of the infection. 25
Frequent recurrent outbreaks
People who have frequent cold sore outbreaks (6 or more per year) should visit a healthcare provider to discuss preventive strategies and long-term treatment options. Daily oral antiviral medications may be recommended to reduce the frequency and severity of outbreaks. 26
Sores near the eyes
Cold sores that develop near the eyes or on the eyelids need prompt medical attention, as the infection can spread to the eye and cause a serious condition called herpetic keratitis. Symptoms of herpetic keratitis include eye pain, sensitivity to light, discharge, and blurred vision. If left untreated, this condition can scar the cornea and cause permanent vision loss. 27
Complications in high-risk people
Certain groups of people are at a higher risk of developing severe complications from cold sores and should seek medical care when an outbreak begins:
- Newborns: Neonatal herpes can happen when a baby is exposed to HSV during birth, and it can cause serious complications such as brain damage, blindness, or even death. Pregnant women with active genital herpes lesions should let their healthcare provider know to lower the risk of transmission during delivery.
- Immunocompromised people: People with weakened immune systems due to conditions like HIV/AIDS, cancer, or organ transplantation are more susceptible to severe and prolonged cold sore outbreaks. They may also be at risk for the virus spreading to other parts of the body, such as the brain or lungs.
- People with eczema: People with atopic dermatitis (eczema) are at risk for a serious condition called eczema herpeticum, which happens when HSV spreads across the skin, causing widespread blistering and fever. This condition needs immediate medical attention and treatment with oral antiviral medications. 28,29,30
What to expect at a medical appointment
During a medical appointment for cold sores, the healthcare provider will typically:
- Review the patient's medical history and symptoms
- Perform a physical examination of the affected area
- Take a sample from the sore for laboratory testing to confirm the presence of HSV, if necessary
- Discuss treatment options based on the severity and frequency of outbreaks
- Provide guidance on what you can do to treat and prevent the spread of infection 31
The healthcare provider may prescribe oral antiviral medications to help speed up healing and reduce the duration of symptoms. For severe or complicated cases, the provider may recommend additional tests or refer the patient to a specialist, such as a dermatologist or infectious disease expert. 31,32
Conclusion
Cold sores are a common and contagious viral infection caused by the herpes simplex virus. While they can be painful and unsightly, most cold sore outbreaks resolve on their own within 7-10 days. However, treatment options including antiviral medications, home remedies, and self-care measures, can help manage symptoms, speed up healing, and reduce the frequency of outbreaks.
For people experiencing severe, persistent, or frequent cold sores, it is important to seek medical attention to prevent complications and explore long-term treatment options.
By understanding the causes, symptoms, and treatment options for cold sores, you can take proactive steps to manage this common condition and minimize its impact on your quality of life.
Citations:
<1>Mayo Clinic. (n.d.). Cold sore - Symptoms and causes. https://www.mayoclinic.org/diseases-conditions/cold-sore/symptoms-causes/syc-20371017</1>
<2>WebMD. (n.d.). Cold Sores: Causes, Symptoms, Treatment, Complications, and Prevention. https://www.webmd.com/skin-problems-and-treatments/understanding-cold-sores-basics</2>
<3>Johns Hopkins Medicine. (n.d.). Cold Sores. https://www.hopkinsmedicine.org/health/conditions-and-diseases/cold-sores</3>
<4>Nemours KidsHealth. (n.d.). Cold Sores (HSV-1) (for Teens). https://kidshealth.org/en/teens/cold-sores.html</4>
<5>Better Health Channel. (n.d.). Cold sores. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/cold-sores</5>
<6>Cliffe, A. R. (2021). Cold sores: Discovery reveals how stress, illness and even sunburn trigger flareups. ScienceDaily. Retrieved from https://www.sciencedaily.com/releases/2021/02/210211113925.htm</6>
<7>Healthline. (2022). The 7 Best Cold Sore Remedies. https://www.healthline.com/health/beauty-skin-care/cold-sore-remedies</7>
<8>WebMD. (n.d.). Cold Sore Remedies: At Home Treatment for Cold Sores. https://www.webmd.com/skin-problems-and-treatments/cold-sores-at-home-care</8>
<9>Healthline. (2022). How to Get Rid of a Cold Sore Fast: Treatments and Home Remedies. https://www.healthline.com/health/how-to-get-rid-of-a-cold-sore-fast</9>
<10>WebMD. (n.d.). Understanding Cold Sores -- Treatment. https://www.webmd.com/skin-problems-and-treatments/understanding-cold-sores-treatment</10>
<11>betterhealth.vic.gov.au. (n.d.). Cold sores. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/cold-sores</11>
<12>Cedars-Sinai. (n.d.). Cold Sores. https://www.cedars-sinai.org/health-library/diseases-and-conditions/c/cold-sores.html</12>
<13>Garcia-Linares, M. I., Sanchez-Lorente, S., Coe, C. L., & Martinez, M. (2004). Intimate male partner violence impairs immune control over herpes simplex virus type 1 in physically and psychologically abused women. Psychosomatic Medicine, 66(6), 965-972. https://doi.org/10.1097/01.psy.0000145820.90041.c0</13>
<14>Cohen, S., Tyrrell, D. A., & Smith, A. P. (1991). Psychological stress and susceptibility to the common cold. New England Journal of Medicine, 325(9), 606-612.</14>
<15>Freedy, J. R., Shaw, D. L., Jarrell, M. P., & Masters, C. R. (1992). Towards an understanding of the psychological impact of natural disasters: an application of the conservation of resources stress model. Journal of Traumatic Stress, 5(3), 441-454.</15>
<16>Mayo Clinic. (n.d.). Cold sore - Diagnosis and treatment. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/cold-sore/diagnosis-treatment/drc-20371023</16>
<17>WebMD. (n.d.). Cold Sore Treatments. WebMD. https://www.webmd.com/skin-problems-and-treatments/understanding-cold-sores-treatment</17>
<18>Cleveland Clinic. (n.d.). Cold Sore: Causes, Treatment & Prevention. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/21136-cold-sores</18>
<19>Abreva. (n.d.). Cold Sore Stages: How Long Do Cold Sores Last?. Abreva. https://www.abreva.com/about-cold-sores/cold-sore-stages/</19>
<20>Healthline. (n.d.). 6 Causes and Triggers of Cold Sores. Healthline. https://www.healthline.com/health/6-causes-and-triggers-of-cold-sores</20>
<21>Abreva. (n.d.). What Causes a Cold Sore? What Triggers Cold Sores?. Abreva. https://www.abreva.com/about-cold-sores/what-triggers-your-cold-sores/</21>
<22>Semprini, A., Braakhuis, A. J., Campion, V., Leach, M. J., & Spitzer, K. (2019). Kanuka honey versus aciclovir for the topical treatment of herpes simplex labialis: a randomised controlled trial. BMJ open, 9(5), e026201.</22>
<23>Garozzo, A., Timpanaro, R., Stivala, A., Bisignano, G., & Castro, A. (2009). Activity of Melaleuca alternifolia (tea tree) oil on influenza virus A/PR/8: study on the mechanism of action. Antiviral research, 83(1), 19-25.</23>
<24>Garozzo, A., Timpanaro, R., Bisignano, B., Furneri, P. M., Bisignano, G., & Castro, A. (2009). In vitro antiviral activity of Melaleuca alternifolia essential oil. Letters in applied microbiology, 49(6), 806-808.</24>
<25>Godfrey, H. R., et al. (2001). A randomized clinical trial on the treatment of oral herpes with topical zinc oxide/glycine. Alternative Therapies in Health and Medicine.</25>
<26>Jensen, L. A., et al. (2004). Oral antivirals for the acute treatment of recurrent herpes labialis. Annals of Pharmacotherapy.</26>
<27>McCarthy, J. P., et al. (2012). Treatment of Herpes Labialis: Comparison of Two OTC drugs and untreated controls. Journal of Esthetic and Restorative Dentistry: Official Publication of the American Academy of Esthetic Dentistry.</27>
<28>Rocha, M. P., Amorim, J. M., Lima, W. G., Brito, J. C. M., & Nizer, W. S. C. (2020). Effect of honey and propolis, compared to acyclovir, against Herpes Simplex Virus (HSV)-induced lesions: A systematic review and meta-analysis. Biomedicine & Pharmacotherapy, 129, 110409.</28>
<29>Abreva. (n.d.). What type of antiviral cold sore medication is right for me? Retrieved from https://www.abreva.com/managing-lip-health/cold-sore-triggers/what-antiviral-cold-sore-medication-is-right-for-me/</29>
<30>NHS. (n.d.). Aciclovir: medicine for cold sores, chickenpox and shingles. Retrieved from https://www.nhs.uk/medicines/aciclovir/</30>
<31>Rocha M.P., Amorim J.M., Lima W.G., Brito J.C.M., Nizer W.S.C. Effect of honey and propolis, compared to acyclovir, against Herpes Simplex Virus (HSV)-induced lesions: A systematic review and meta-analysis. Biomedicine & Pharmacotherapy. 2020;129:110409. doi:10.1016/j.biopha.2020.110409.</31>
<32>Stock, C., Guillemin, I., Pichon, M. F., & Stoebner, P. (2001). Risk factors of herpes simplex type 1 (HSV-1) infection and lifestyle factors associated with HSV-1 manifestations. Sexually Transmitted Infections, 77(3), 183-187.</32>
<33>Up to 80% of the population has HSV-1, which causes cold sores, and up to 22% of sexually active adults have genital herpes caused by HSV-2 (Myths vs facts on genital herpes (HSV-2) & cold sores, 2023).</33>
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