Fever Blister- Causes, Symptoms and Treatment

A fever blister is commonly known as a cold sore.It is a group of tiny blisters that is situated either in or near the mouth. Commonly it is situated on the border of the lips.

It may also be located at chin, nostrils, cheeks, the palate and gums.It is highly contagious and spread by skin contact and saliva. Saliva may be passed while kissing, touching and sharing utensils or razors.

Image Source: nhs.uk
Image Source: nhs.uk

It may spread to other parts of the body such as eyes and genitals. If you have fever blister be very cautious and do not touch it.

The causative agent of fever blister is Herpes simplex virus type 1. Most of us get infected by this virus before we reach the age of 10 years. In every 8 among 10 individual, this virus is present in a dormant stage and may become active anytime.

Factors that reactivate HSV type-1 virus are as follows:

  • Mental, emotional and physical stress.
  • Sunburn
  • Cold or fever
  • Dental illness
  • Lip trauma
  • Food allergies
  • Impaired immune system
  • Pregnancy
  • Hormonal changes
  • Cosmetic surgeries

The virus causing Fever blister may cause serious illness that may be life-threatening in individuals with weak immune system.


Let’s give a quick look to the symptoms of fever blister:

If infected for the first time you may suffer from following symptoms after a week of incubation period:

  • Headache
  • Fever
  • Nausea and vomiting
  • Painful swelling
  • Open sores, especially in the mouth
  • Sore throat

However, some people may not develop any symptoms when they are infected for the first time.

After the first infection, the HSV-1 virus remains dormant in facial nerves and may cause recurrent fever blisters.

Common symptoms of  recurrent fever blisters are:

  • Burning, itching, numbness and pain are present before blisters burst.
  • Blisters that burst open, leaks fluid that is clear, crusts and finally sheds. It may take a week or 2 to heal.
  • The surrounding area is swollen and red.
  • Sore mouth
  • A sore throat
  • Swollen lymph nodes
  • Drooling in small kids.
  • Difficulty in sleeping, eating and drinking.

Individuals who are at risk of fever blisters are:

  • Having a weak immune system
  • Children 1 to 3 years of age.
  • Individuals under stress.
Image Source: newkidscenter.com
Image Source: newkidscenter.com

 How to treatment- There no cure of fever blisters. It usually heals on its own.

  • Medicines may relieve some of the symptoms and may prevent an outbreak in the future.
  • In the case of the first outbreak, oral antivirals are prescribed.
  • In the case of recurrent fever blisters, the doctor may prescribe topical creams and ointments to reduce pain, itching and to promote healing. Oral antiviral drugs are usually given after first symptoms by doctors prescribing.
  • The doctor may also prescribe a higher dose of oral antiviral in the case of a weakened immune system.
  • Vitamin C and lysine supplements may be given to promote healing.

When to see a doctor:

  • If blisters persist for more than a week.
  • Difficulty in swallowing.
  • High fever
  • Second, frequent outbreak.

Preventive measures:

A fever blister is a lifelong suffering. Following are the preventive measures to prevent its outbreak:

  • Apply sunscreen on your lips before going out in the sun.
  • Keep yourself hydrated during fever.
  • Reduce stress.
  • Avoid touching, kissing and sharing utensils, especially with people who have signs of fever blisters.

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