Cold Sore Outbreak Overview

The small blisters around the mouth and nostrils that define cold sores (also known as fever blisters) are due to a virus that, once contracted, stays with you, hiding until triggered. Anyone can get a cold sore, and most people contract the virus through physical contact with an affected person. Once you get it, the virus responsible for cold sores stays with you for the rest of your life, hiding until triggered. Even without a visible cold sore, a person can infect others via their saliva.

Researchers have found that more than half of Americans ages 14 to 49 carry the herpes simplex virus type 1 (HSV)—the virus that causes cold sores to develop—and up to 90 percent of Americans will have at least one cold sore during their lifetime.

Cold sores are generally harmless in most healthy adults, but they’re also extremely contagious. Many people don’t realize when they’re being exposed to the virus through physical contact with an infected person. Kissing and intimate contact, as well as sharing food, drinks, and personal items (e.g., lip balm, razors, or towels) can put you at risk of contracting herpes simplex.

In one 2014 report in the journal Human Genome Variation, researchers suggested that a susceptibility gene is the main risk factor for cold sores. However, the exact mechanism of such a gene is unknown.

Once infected with herpes simplex, you will have the virus for the rest of your life. Recurrent cold sore outbreaks can be triggered by many different factors like stress, fatigue, hormonal changes (including menstruation), illness, dental work and even exposure to extreme weather.

The HSV virus generally remains dormant in the body, which means you won’t present any symptoms unless it is reactivated. Many carriers of the herpes simplex virus never experience symptoms or an outbreak.

When someone does experience a breakout, symptoms become apparent within a few days of exposure to the HSV virus. After the first infection, the virus is dormant, hiding inside the nerve cells of the face, which means symptoms may not be experienced. However, triggers can lead to recurrences of the virus. 

Symptoms may include:

• Red, fluid-filled blisters around the lips and occasionally on the nose or cheeks
• Pain in affected areas
• Fluid secretion from blisters
• Formation of scabs after blisters have dried
• Itching and irritation of affected areas
• Mild fever
• Headache
• Swollen lymph nodes
• Muscle aches or general body pain
• Difficulty swallowing
• Fatigue

If you’re experiencing your first outbreak, you may have fluid-filled blisters as well as flu-like symptoms, such as fever, sore throat, headache, swollen lymph nodes, and body aches.

If you’re experiencing a recurrence, expect to develop blisters in the same place as previous outbreaks; the virus reactivates in the same spot each time. You can expect fewer severe symptoms with a recurrence, as the severity of outbreaks generally lessens over time.

Children can develop cold sores inside the mouth, which are commonly mistaken for canker sores (small lesions in the mouth). If your child begins to develop sores in the mouth, see the pediatrician as soon as possible. The doctor will be able to provide an accurate diagnosis based on a physical exam and other present symptoms.

After initial symptoms develop, it can take two to four weeks to heal completely. During that time, cold sores go through three distinct stages. The symptoms and stages of an outbreak can vary depending on whether or not this is your first case or a recurrence.

During the first stage of a cold sore outbreak—or the first one to two days, approximately—many people experience tingling, itching, or even soreness around the mouth. If you’re having a recurrence, you’ll likely feel these sensations in the same locations as previous outbreaks. Some people experience these sensations and never actually develop fluid-filled blisters. 

After a few days, small, hard, fluid-filled blisters begin to form on the lips, nose, cheeks, or other parts of the face. If you develop a blister (or blisters) near the eyes, make an appointment with an eye doctor immediately. Watch out for eye symptoms, such as sensitivity to light, pain, or grittiness in the eyes.

At this stage, the blisters and fluid are extremely contagious, so it’s important to avoid close physical contact with others. You can also spread blisters to other locations on the body by touching sores and then another body part. If you touch a cold sore, wash your hands immediately. 

The blisters may merge together and burst, resulting in small, open sores that ooze fluid. These sores are very painful and highly contagious. After a few days, the open sores will begin to dry out and scab. Scabs can be very itchy and even crack, so avoid biting or picking at them, as this can worsen discomfort.

Between five and 15 days after the initial outbreak, scabs will begin to fall off and affected areas will begin to heal.

Until cold sores have scabbed over, you can still infect others. Until then, be sure to avoid:

• Touching cold sores
• Kissing
• Intimate contact (e.g., oral sex)
• Sharing food, drinks, or personal items
• Having physical contact with anyone who has a weakened immune system
• Having physical contact with children

Cold sores can cause serious health issues in newborns, children, and people with a weakened immune system. It is, therefore, important to remain vigilant and take steps to avoid infecting others with HSV.

Cold sores cause pain, irritation, and even embarrassment. Fortunately, there are a number of ways to treat pain and symptoms to feel better faster.

If taken within 72 hours of an outbreak, certain oral antiviral medications (prescribed by your doctor) can help shorten the time it takes for cold sores to heal. For recurrences, be sure to talk to your doctor or dermatologist about prescription treatments.

Your doctor may also recommend applying antiviral ointments directly to your cold sores. Remember to wash your hands immediately after applying topical medicines.

Over-the-counter pain relievers such as Advil (ibuprofen) or Tylenol (acetaminophen) can alleviate pain, swelling, and irritation caused by blisters or open sores.

A cold compress can reduce pain and irritation. Be sure to use a cool, damp towel, rather than an ice pack. Apply compresses a few times each day for five to 10 minutes at a time.

Otherwise, keep the affected area clean and dry, and avoid applying make-up over cold sores. Also, stay away from foods that worsen symptoms. Anything acidic, such as citrus, tomatoes or coffee, can irritate cold sores and prolong symptoms.

Your doctor can get cold sores under control so as to avoid potential complications, which may include ocular herpes (HSV-1 transfer to the eyes) and various skin infections.

Fortunately, cold sores tend to be harmless and clear up within a few weeks. If you start to develop symptoms of a cold sore outbreak, and especially if outbreaks are recurrent, talk to your doctor about the best treatment plan for your age, medical history, and lifestyle.