Cold Sore Blisters

​Cold sores, also known as fever blisters, are small, fluid-filled lesions that typically appear on or around the lips. They are caused by the herpes simplex virus (HSV), primarily HSV-1. Once infected, the virus remains in the body and can reactivate, leading to recurrent cold sores. ​

Symptoms of Cold Sores

A cold sore usually progresses through several stages:​

  1. Tingling and Itching: Many individuals experience a tingling, itching, or burning sensation around the lips a day or two before a small, hard, painful spot appears and blisters erupt. ​
  2. Blisters: Small fluid-filled blisters typically erupt along the border of the lips. ​
  3. Oozing and Crusting: The blisters may merge and then burst, leaving shallow open sores that will ooze fluid and then crust over. ​

Cold sores are contagious from the moment you first feel tingling or other signs of a cold sore coming on to when the cold sore has completely healed. ​

Triggers for Recurrence

Certain factors can trigger the reactivation of the HSV, leading to the development of cold sores:​

  • Illness or Fever: Being unwell can trigger a cold sore. ​
  • Sun Exposure: Exposure to sunlight can trigger a cold sore. ​
  • Menstruation: Being on your period can trigger a cold sore.

Help and Advice from the Pharmacy

While cold sores usually clear up without treatment within 7 to 10 days, several interventions can reduce symptoms and speed up healing:​

Over-the-Counter (OTC) Treatments:

  • Antiviral Creams: Topical creams containing antiviral agents, such as aciclovir, can help ease symptoms and speed up healing time. These creams are most effective when applied at the first sign of a cold sore. ​
  • Pain-Relief Creams: OTC creams can ease pain and irritation. ​
  • Cold Sore Patches: These patches protect the skin while it heals.

    Self-Care Measures

    In addition to medications, certain self-care strategies can help manage symptoms and prevent the spread of infection:​

    • Avoid Triggers: Identify and avoid factors that trigger cold sores, such as sunbeds. ​
    • Sun Protection: Use sunblock lip balm (SPF 15 or above) if you’re outside in the sun. ​
    • Pain Management: Take paracetamol or ibuprofen to ease pain and swelling. ​
    • Hydration: Drink plenty of fluids to avoid dehydration. ​

    Preventing Transmission

    Cold sores are highly contagious. To prevent spreading the virus:​

    • Hand Hygiene: Wash your hands with soap and water whenever you touch your cold sore.
    • Avoid Kissing: Do not kiss anyone while you have a cold sore. ​
    • Avoid Oral Sex: Do not have oral sex until your cold sore completely heals, as you could give your partner genital herpes. ​
    • Avoid Sharing Items: Do not share items that come into contact with the mouth, such as lip balm, cutlery, or towels, during an outbreak. ​

    When to Seek Medical Advice

    While most cold sores resolve without medical intervention, consult a GP if:​

    • The cold sore has not started to heal within 10 days. ​
    • You’re worried about a cold sore or think it’s something else. ​
    • The cold sore is very large or painful. ​
    • You or your child also have swollen, painful gums and sores in the mouth (gingivostomatitis). ​
    • You have a weakened immune system – for example, because of chemotherapy or diabetes. ​

    In such cases, a GP may prescribe antiviral tablets or refer you to a specialist for further evaluation and treatment. ​

    Updated on April 3, 2025
    Was this article helpful?

    Related Articles

    Leave a Comment