Fever blisters

Definition: What are fever blisters?

Fever blisters are small blisters filled with liquid that occur repeatedly at certain locations. Most often, fever blisters are found on the lips or in the mouth. They are caused by the Herpes Simplex Virus Type 1 and are also known as cold sores.

Many different ointments and creams are used for treatment. Fever blisters are ultimately harmless, but very unpleasant for those affected. It can take up to 14 days before the blisters disappear again.

Causes and pathogens of fever blisters

The cause of fever blisters is an infection with the Herpes Simplex Virus Type 1, which most people carry in their bodies, but not all virus carriers regularly get fever blisters. There are indeed various risk factors that can cause the outbreak of cold sores. Fever blisters occur mainly when the immune system is weakened.

This is the case with stress. But the sun also weakens the skin and promotes the appearance of blisters. Drugs such as cortisone, which suppresses the immune system, also lead to the development of fever blisters more easily.

Fever blisters do indeed usually appear when you can use them the least. This is especially the case when skiing or on a summer vacation. The reason for this is the sun.

The sun’s radiation on the skin reactivates the virus that causes the fever blisters. This is because UV radiation often prevents the immune system from performing its monitoring function without restriction. And the virus slumbering in the cells can more easily cause an infection.

The risk of fever blisters is particularly increased when other factors such as stress or an infection of the upper respiratory tract are added. Emotional stress is an important risk factor for the occurrence of fever blisters. All affected patients know this.

Similar to sun exposure, stress leads to a reduction of the immune system. It is easier to catch a cold. Infections of the upper respiratory tract also promote the occurrence of fever blisters. But even without a cold, one has a high risk of developing lip herpes under stress.