Cold Sore

Overview of Cold Sore

A cold sore is a lesion that forms on the skin surface usually around the mouth. It is also called a fever blister. They are tiny and fluid-filled. Usually, they develop on the lips and occur in groups or patches.
Cold sores are contagious and can spread through kissing or touching the infected area. They can also be spread by oral sex.

Prevalence of Cold Sore

More than 50 percent of people suffer from a cold sore. It is a very common viral infection all over the world. Prevalence in Pakistan is very low.

Signs and Symptoms of Cold Sore

Signs and symptoms include:

  • Fluid-filled blisters
  • Tingling and itching around the lips
  • Oozing of the blisters followed by crust formation
  • Fever
  • Sore throat
  • Painful gums
  • Headache

Types of Cold Sore

Causes of Cold Sore

They are caused by the Herpes simplex virus:

  • HSV-1
  • HSV-2

HSV-1 is commonly responsible for cold sores but HSV-2 can also cause cold sores.
This infection can be triggered by:

  • Stress
  • Fever
  • Infection
  • Fatigue
  • Skin injury
  • Weakened immune system

Possible risk factors include:

  • Eczema
  • AIDS
  • Chemotherapy
  • Anti-rejection drugs

Risk Factors of Cold Sore

The occurrence of a cold sore is heightened in the presence of the following risk factors:

  • Long term exposures to the sunlight
  • Infections
  • Fevers
  • Dental implants or surgery
  • Menstruation
  • Excessive exercise
  • Medications
  • Previous medical history
  • Emotional stress
  • Physical injury

Complications of Cold Sore

Following are the health complications associated with cold sores:

  • Skin Infections

When the virus comes into contact with broken or injured skin it can result in infections.

  • Whitlow Finger

 This condition leads to the development of sores on the fingers.

  • Herpetic Keratoconjunctivitis

This leads to swelling and irritation in the eyelids.



A cold sore is a disease that can be prevented with the help of the following strategies:

  • Pay close attention to your personal hygiene
  • Avoid being in contact with an infected person’s body fluids
  • Make sure to use sunscreen and lip balm
  • Make sure to wash your hands frequently
  • Avoid those things that trigger cold sores
  • Do not share your utensils with another person who may have cold sores


A diagnosis can be given simply by looking at the blisters. In some cases, a blister sample might be taken for further testing.

Treatment of Cold Sore | When to Consult a Doctor

Cold sores usually go away on their own in 2 to 4 weeks. Antiviral medications may be given. Topical medications are applied directly on the blisters. For severe cases, antiviral drug injections might be given.
If the cold sore persists or bleeds, immediately consult a dermatologist. Do not take any form of medication without consulting a doctor.