Cold Sores (Herpes Labialis)
Cold sores (or fever blisters) are a viral infection characterized by fluid-filled blisters that appear on or around the lips. When they rupture, they form ulcers and eventually scab over. They are highly contagious.
There is no complete cure for cold sores, but certain measures can help manage the condition and reduce the frequency of outbreaks.
Causes
Cold sores are caused by certain strains of the herpes simplex virus, usually type 1 (HSV-1), although they can also be caused by HSV-2 (the virus that typically causes genital herpes).
The virus is transmitted through direct contact and remains dormant without symptoms until it is triggered. Outbreaks may be brought on by one or more of the following factors:
- Cold weather – Lips may become cracked, making them more prone to infection.
- Sun and wind exposure – These can damage the lips, similar to cold weather.
- Hormonal changes – Such as those occurring during menstruation.
- Immunosuppression, caused by:
- Stress
- AIDS (HIV)
- Seasonal factors – Immunity tends to decrease in autumn and winter
- Other illnesses
- Chemotherapy medications for cancer
- Medications used to prevent organ transplant rejection
Symptoms
Before the blister appears, a burning and itching sensation is usually felt in the area where it will develop, which later becomes firm.
The blister gradually forms and fills with fluid until it bursts. Over time, it may ooze and dry out, forming a scab that will fall off shortly afterward. Blisters often appear in clusters and may merge into a larger one.
Although less common, blisters can also appear beyond the lips, on the cheeks and chin, and even inside the nostrils and mouth (on the palate or gums).
Some people may carry the virus without ever developing symptoms.
The first outbreak is usually the most severe and is often accompanied by additional symptoms such as:
- Headache, sore throat, and muscle aches
- Fever
- Swollen lymph nodes
- Gum inflammation and pain
In subsequent outbreaks, these general symptoms usually decrease or disappear, and the condition is limited to the appearance of blisters.
Diagnosis
For a healthcare professional, diagnosing cold sores is usually straightforward based on visual examination. If there is any doubt, a sample may be sent to the laboratory for analysis.
Treatment
Symptoms generally resolve on their own within a couple of weeks.
To shorten the duration of an outbreak, antiviral medications may be prescribed, including penciclovir, valacyclovir, or acyclovir. Some are applied as creams, while others are taken in pill form.
To relieve pain, topical anesthetic creams (such as benzocaine or lidocaine) may also be recommended. Cold, moist compresses applied to the blisters can help reduce pain and promote healing.
Careful hygiene is essential during outbreaks. Hands should be washed frequently, and touching the sores should be avoided, as the infection can spread to other areas of the body, including the eyes.