What is it?
Cold sores, also known as fever blisters or orofacial herpes simplex, are common viral infections that cause contagious sores and localized blistering. Considered self-limiting in most cases, they typically form on or near the lips and inside the mouth.
They are caused by Herpes Simplex Virus (HSV) type 1 or 2. HSV Type 1 is the most common cause of cold sores as it is commonly transmitted via saliva; however, HSV Type 2 can also cause cold sores (although it is usually the culprit in genital herpes since it is present in genital secretions) through activities like oral sex. HSV infections are not restricted to the above mentioned areas but can infect other parts of the body as well.
Once infected, HSV remains in a dormant state in the body for life. HSV may not cause symptoms again or it may occasionally reactivate and cause symptoms in the same area as previous. This is because the virus lies in a dormant state inside the collection of nerve cells known as the ganglia near the spinal cord that supply nerve fibers to the infected area. When the virus is triggered, it begins multiplying again and travels through the nerve fibers back to the skin, where it causes the blisters.
Not all patients will experience symptoms (as the majority of people who carry the virus do not know they do) but it is a common problem affecting up to 80% of adolescents and adults.
What are the symptoms?
The spectrum of symptoms can range for each person; however, the first episode tends to be the worst. The first infection usually happens during childhood (HSV Type 1). It may present with a fever (that subsides after 3 to 5 days), restlessness, swollen lymph nodes, and foul breath. Eating and drinking can be painful as the blisters form on the tongue, throat, palate and inside the cheeks. Blisters pop and form scabs that eventually fall off. Gums may be swollen, red and bleed easily. Recovery usually occurs within three weeks. Of the patients who experience a first infection, 20% to 40% may develop recurrences. Subsequent recurrences tend to be less severe.
Common symptoms of recurrent cold sores are milder and generally last up to 8 days, targeting most often the lips. Prior to eruption, cold sores may be preceded by pain, burning, tingling or itching 2 to 24 hours before their their appearance (prodrome).
The skin around the blister is often red. The blisters break and leak a clear, sticky fluid that crusts over and heals without scarring within 7 to 10 days. The most common symptoms complained about are itching, pain and the unsightly appearance.
What are triggers and what can I do to prevent the spread of cold sores?
Cold sores are typically triggered by:
- Hormonal factors (menstruation, pregnancy)
- Physical trauma (like dental procedures, cuts from shaving)
- Upper respiratory tract infections
- Temperature extremes
- Weakened immune system
Oftentimes, the trigger is unknown. However, if you are aware of your triggers, you may be able to prevent them from occurring. If sunlight is a trigger, use a lip balm with at least SPF 30 or higher, applied 30 minutes prior to exposure. Reducing stress through eating well, getting enough sleep and exercise, and relaxation may help prevent recurrences. Sometimes a course of antivirals may be prescribed for you prior to a triggering event (dental procedures, sun exposure). Please discuss with your doctor.
HSV infections are very infectious. They can be easily transmitted from one individual to another. Although cold sores may be transmitted at any time, they are more likely to spread during an active infection. When experiencing an active infection, do not: kiss anyone, share utensils, glasses, water bottles, towels, lip cosmetics, razors, toothbrushes or give anyone oral sex. Do not have skin to skin contact with young children, pregnant women, people who have eczema, or people who have a weakened immune system (cancer, HIV, organ transplant recipient). Do not touch your own cold sores as you can spread it to other parts of your own body. Always practice good hand hygiene.
When should I see the doctor?
There are situations where further assessment by a doctor is necessary. These include (but not limited to):
- If you are experiencing other symptoms such as fever, swollen glands, malaise
- If the symptoms are severe and it prevents from swallowing fluids and the like
- If blisters are present for more than 2 weeks
- If the lesions look infected (excessively red, swollen or contain pus)
- If lesions are recurring more than six times a year (preventative treatment may be helpful, although it won’t prevent infected people from transmitting the infection)
- If the patient has a weakened immune system
What can be done to make it feel better?
For mild symptoms, treatment isn’t necessary. Simple covering of the blisters may be sufficient. There is no cure once the virus is contracted but luckily symptoms usually become milder with time.
Antivirals are a staple of treatment for cold sores. The oral antivirals are considered more effective than the topical formulations (decreasing symptom duration by 1 to 2 days as opposed to half a day). Antivirals reduce symptoms and shorten the duration of an episode.
They will not abort a lesion entirely. They are best initiated within a few hours of symptom onset (the tingling, burning or itching prior to the actual appearance of the lesion). Antivirals do not provide any benefit if lesions have already appeared.
The only over-the-counter non-prescription antiviral for cold sore use is Docosanol 10% (also known as Abreva). Abreva helps prevent HSV from spreading to healthy cells. It is a safe and effective topical treatment that needs to be applied five times daily at the first sign of symptoms for 5 to 10 days. Side effects include mild and infrequent stinging. There are no significant drug interactions. It may decrease the duration of painful symptoms and time to healing by 17 to 79 hours.
Other non-medicinal measures that may help include applying ice to the affected area, which may soothe and minimize swelling. Alternatively, you can use cool, tap water compresses to soak the area. Keep the infected area clean with gentle washing of soap and water. Stay hydrated but avoid hot beverages, spicy and salty foods, and citrus fruits or juices which may exacerbate the pain.
Keeping the area moist will keep it from cracking, drying and getting infected. An ointment (such as calamine, cocoa butter, petrolatum, or zinc oxide) can be helpful and applied with a clean, cotton-tipped swab (Q-tip). Topical anesthetics (such as Zilactin B or Anbesol) may help minimize the pain temporarily or the use of oral pain relievers (such as Tylenol or Advil) which are recommended for moderate to severe pain can be used for up to 3 days.
References available on page 2.