A cold sore which erupts on our facial skin is a fluid-filled lesion, that is caused as a result of the spread of the herpes simplex virus of type 1 infection. It is technically known as Herpes labialis. The sore may or may not occur during a herpes simplex infection. In a type 1 infection, the sores are facial and are commonly referred to as cold sores or fever blisters. The type 2 infection results into genital sores.


The herpes simplex virus is principally a skin infection that causes cold sores and fever blisters to break out on the face. Most of the time it is the type 1 infection, which is depicted by facial lesions. The time span of the sores extends to about a fortnight or so. The common symptom on the first two days is typically a tingling, itchy, and irritating sensation on the facial skin that surrounds the mouth and nose. This preceding stage is known as the prodrome. Some sores also occur inside the mouth or the nasal cavity. Usually, they start appearing after your body has been exposed to the herpes simplex virus for about a week or so, maybe even 10 days. Sometimes, the symptoms do not occur for more than 20 days. The itching, tingling, and irritating scratchy sensation is followed by a certain small outbreak of sores on the softer areas of the skin. These sores gradually become fluid-filled and painful. Following this, they turn into painful blisters which become hard. Later, these blisters rupture, and pus oozes out of them. A yellow crust gets formed on the sore, which is followed by the exposure of the underlying pink skin.

The formation of pink skin is usually the sign that the infection of the virus has receded, or has been eradicated by the antibodies of the body. However, there is also a possibility that the infection has taken refuge in the nerves, which may reappear. Apart from the painful sores, there are several reasons as to why one should seek treatment as soon as possible. One of the reasons is that, the infection is highly contagious, and it can spread easily by hugging, using the same utensils, clothing, towels, etc. Also, the infection may lead to some or the other ailments such a severe fever, declined immunity, etc.

Acyclovir as a Medication

Cold sores and can be treated with the help of acyclovir, which is also known as aciclovir, acycloguanosine, and ACV. It is a guanosine analog antiviral drug, which has been used in treating viral fever since the end of 1980s.

Medical practitioners have noted acyclovir to be a selective medication with low cytotoxicity (the property of being toxic to cells), and also being a prodrug. The process with the help of which this medication triggers the arrest of the simplex virus is very, very complicated. However, being a prodrug, acyclovir enters the human system in an inactive form. Once in the body, this prodrug gets metabolized to form an active metabolite. This process is known as bio-activation. Once activated, it acts as a bounty hunter by arresting the virus and bringing it out in front of a panel of judges, that consist of antibodies formed by the body and white blood cells.

The basic process works in such a way that this prodrug prevents the replication of viruses. Most of the viruses devour normal cells by taking over the entire cell. A cell component known as the 'nucleoside' is used by the virus to manufacture appropriate DNA for replication and multiplication. The virus itself converts acyclovir into an active form, which later gets incorporated into the newly made viral DNA. This activated prodrug tends to freeze the DNA production, thereby stopping the virus replication process. By that time, the antibodies which are produced by the body swiftly execute the herpes simplex virus.

Acyclovir is known as the best selective remedy against herpes virus family, which consists of herpes simplex, varicella zoster, epstein-barr, and cytomegalovirus. It is a prescription drug that is marketed under the name 'Zovirax', and is available in several forms such as ointments, tablets, capsules, and injections.

Disclaimer: This Buzzle article is for informative purposes only, and should not be used as a replacement for expert medical advice.