Cold sores are also known as ‘fever blisters’ or ‘oral herpes’, after the virus responsible for their transmission: Herpes Simplex virus type 1 (HSV-1). They typically appear as a cluster of tiny fluid-filled blisters grouped in one spot of the lip, but are not always isolated to this region. The virus is spread from person to person through skin contact, through saliva, drinking from the same glass/cup or using the same toothbrush, towel or razor.

After the initial infection, certain factors will cause the virus to become reactivated again and a new cold sore outbreak to occur, usually but not always in the same spot as the initial infection. 

There is no cure for cold sores, but there is a lot of advice available as to how you can best manage the condition - something that our private GP's at London Doctors Clinic regularly advise patients on. 


Cold Sore Symptoms

Whether it’s an initial outbreak or a re-occurrence there are generally 5 stages to a cold sore

  1. Prodromal stage: 1-2 days
    • In the majority of cases, the first indication that a cold sore is forming is the sensation of tingling, itching, stinging, or soreness in the area where the cold sore will eventually appear. The area may become slightly raised or reddened.
  2. The Blister stage: 2-3 days
    • Following the prodromal phase, there will be the formation of a few fluid-filled blisters. The area may become quite sore at this stage.
  3. The Weeping stage: 1-3 days
    • The blisters rupture and clear fluid may be released. This is the stage where someone is most likely to pass on the virus. This stage can be the most painful stage.
  4. The Crusting stage: 3-4 days
    • A scab will form over the cold sore, which might become quite dry. They often crack or break which might result in some bleeding. This phase might be quite itchy.
  5. The Healing stage: 3-4 days
    • The cold sore will continue to scab and get smaller and smaller until it resolves. Most cases of cold sores resolve without causing permanent scars.

You may also notice additional symptoms such as fever, muscle aches or swollen lymph nodes around your neck.


Cold Sore Triggers 

Even though you may not be able to see a cold sore, once you have acquired the virus, it will always be present in your body after the initial infection. It ‘goes to sleep’ between outbreaks and lays dormant in nerves in the body. There are certain triggers for cold-sore outbreaks that are unique to each individual, but some common triggers include:

  • Sun exposure
  • Stress
  • Becoming ill or a having weakened immune system
  • Having your period (women only!)
  • Having surgery
  • Eczema
  • Dental work


Cold Sore Treatment

There is no cure for a cold sore but there are several ways to hurry up the healing process when you do start seeing the early symptoms of a cold sore.

  1. Topical creams
  • If you first start noticing the early signs of a cold sore such as tingling, itching or swelling of the lip, aciclovir (Zovirax) is one of the most effective ways of preventing the cold sore progressing and may ease the severity of the outbreak. It is available over the counter at any pharmacy and should be applied as soon as you first start to notice the outbreak.
  1. Oral medications
  • Oral anti-virals can be prescribed to help those that get severe outbreaks or those that are immunocompromised. Medications such as oral acyclovir, valaciclovir (Valtrex) and famiciclovir (Famvir) may be obtained through a quick visit to London Doctors Clinic.



Oral anti-viral medications can be prescribed to help those with severe outbreaks


  1. Home remedies
  • Some of the symptoms of a cold sore may be eased by applying ice directly onto the affected area. It decreases redness and the itchiness of the outbreak.
  • Taking lysine supplements on a regular basis or during an outbreak helps some people to decrease the frequency or severity of the cold sore.
  • Aloe vera or Vaseline won’t necessarily heal a cold sore but it will ease some discomfort while the lesion is present.


Complications of Cold Sores

Usually, cold sores resolve on their own or with the help of some of the methods mentioned above. However, some complications might occur with the initial outbreak that may be cause for concern. If you notice any of the following symptoms, then you should seek medical attention immediately:

  • High or persistent fever
  • Red and irritated eyes
  • Difficulty breathing or swallowing

It’s also important to note that HSV-1 is closely related to HSV-2 (the cause of genital herpes). Both viruses can affect your mouth or genitals, and both viruses can be spread through oral sex.


If you're struggling with frequent outbreaks of cold-sores and want advice on better management of them, or if you've developed a suspect lesion you think may be a cold-sore and want a formal diagnosis, then our experienced GP's here at London Doctors Clinic are happy to help! Simple book an appointment at any of our nine GP surgeries, located across central London. 

By Sophie O'Halloran