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About Cold Sores

What are the signs of a cold sore?

Cold sores, which appear most often around the mouth and the nose, can be very uncomfortable and are associated with the herpes simplex virus (HSV). They are usually of short duration - anything from one week to ten days - and sufferers usually have an attack between one and three times per year, although some people may have as many as twelve attacks per year. They are equally likely to occur in men and women, and can appear at any age.

Before the visible signs of a cold sore appear, most sufferers will experience a tingling sensation, which often precedes the sore itself by 2-3 days. This is an ideal time to start using a topical antiviral cream, if this is appropriate, more details of which can be found below. Small blisters will then form on the skin, which may contain a white substance and cause pain. These blisters then break and the following 'weeping' stage is the stage at which the cold sore is highly contagious. The skin will then scab over.

What are the causes of cold sores?

The herpes simplex virus is responsible for the onset of cold sores. Once infected, the sores will heal and the symptoms will disappear, but the viral infection remains dormant in the facial nerves and is constantly kept in check by the immune system - it cannot be eliminated completely. The initial infection is often in childhood.

There are many factors which can trigger the recurrence of cold sores in a person who has been previously affected; common triggers include stress and fatigue, mouth injuries or dental surgery, menstruation, sunlight, or any other illness or compromise of the immune system.

What complications might occur?

If a cold sore develops in a different area of the face, such as near the eye, the tip of the nose, or inside the nose or mouth, you should see your doctor as this will not be suitable for non-prescription treatments and may develop further if left untreated.

Cold sores are limited to the facial area, however the herpes virus can theoretically infect any part of the body and so it's important to pay attention to personal hygiene - genital herpes is usually caused by a different form of the herpes simplex virus, but infection with the form which causes cold sores is still possible.

Once the weeping stage has passed and a scab has been formed, it's important not to pick this off, as you may be more likely to suffer from a secondary infection in this area.

How can I treat cold sores?

There are many methods to minimise the discomfort of a cold sore, and to prevent it from spreading to other areas of the body or to other people.

  • Wash your hands after touching the sore - if possible, avoid touching it at all
  • Don't touch the eyes or genital areas after touching the sore, without washing your hands
  • Don't scratch or break the scab that forms when the sore is almost healed
  • Do not kiss anyone whilst suffering with a cold sore
  • Use a separate facecloth and towel
  • Identify any factors which could have triggered the cold sore

Once you have identified what causes the sore to recur, you can take preventative action to avoid future episodes; if sunlight is a factor, a sun block cream applied to the face will help, and if cold weather is to blame, a coating of Vaseline on the lips or surrounding area will offer some protection.

What treatments are available for me to purchase?

Products available to purchase without a prescription for the relief and treatment of cold sores can be classified as antiviral products, and soothing or antiseptic products.

Antiviral products The most effective way to treat a cold sore is to use a topical antiviral cream; most non-prescription creams contain an ingredient called aciclovir (such as Zovirax, Soothelip, and Herpetad creams). This is a very effective ingredient which, if used at the tingle stage of a cold sore, can actually stop the sore developing any further; if used at a later stage, aciclovir will reduce the duration of the symptoms by a few days. Aciclovir cream has until recently only been available on prescription, and may now be purchased through pharmacies.

Aciclovir creams should be used five times a day, for five days; treatment may be continued for a further five days if symptoms persist. Because these creams are most effective when used early, you may find it helpful to keep a tube in the house if you are a frequent sufferer.

Soothing or antiseptic products Many products are available to soothe the discomfort of a cold sore, containing ingredients such as cetrimide and iodine (antiseptics), lidocaine (a local anaesthetic), and zinc sulphate (a soothing agent). They do not have any action against the viral infection itself. Many of these are not recommended for use on children; if you have a child with a cold sore, contact our pharmacist for further advice.

When should I see my doctor?

Your doctor should be consulted in any of the following cases:
• Cold sores in infants or young children
• Symptoms which last longer than 2 weeks
• Symptoms which are resistant to the non-prescription treatments listed above
• Cold sores which are painless
• Cold sores affecting the eyes, tip of the nose, or the inside of the nose or mouth

Aciclovir creams in larger quantities are available on prescription, as are oral forms of this antiviral medicine, if the infection requires stronger treatment.

What additional investigations might be needed?

If you suffer from repeated episodes of cold sores which do not respond to treatment, or which do not seem related to any particular trigger factor, your doctor may investigate further to ensure that your immune system is not compromised. If there is an underlying cause for the cold sores, your doctor will decide the most appropriate course of action for you.

Any other information I should have?

Cold sores are very common, and by treating early with non-prescription preparations, and paying special attention to personal hygiene, the discomfort can be minimised effectively. If you have any further questions, ask our pharmacists for more advice.

What are the symptoms of a cold?

The symptoms of colds are varied but will probably include some or all of the following: sore throat, blocked/runny nose, headache, sneezing, coughing, shivering, mild fever, muscular aches and pains in the body generally. A cold should be distinguished from influenza which is a different, and potentially more serious, viral infection.

What are the causes of a cold?

Colds are the result of a viral infection in the upper part of the airway, i.e. the nose, the throat, the voice box and the windpipe. Not all of these parts of the airway will be affected to the same extent.

The virus produces local irritation and inflammation; this in turn causes the inflamed tissues to swell. Many of these are termed 'mucosal' tissues as they normally produce a lubricating fluid (mucus) which moistens the surface and helps trap dust and foreign bodies. If these areas become inflamed they will produce much greater quantities of mucus as a response to the infection. Since the nose is lined with mucosal tissue, this explains the runniness and congestion felt there when you have a cold. Also likely to be affected are the sinuses - air filled cavities lying behind the nose but connected to it by passageways, which are themselves lined with mucosal tissue. If the infection affects the sinuses, they can become filled with mucus, causing sinusitis. On top of the general cold symptoms, you may then suffer from an aching pain around the eyes and nose.


A cold does not generally last beyond 7 to 14 days. If it seems to last beyond that time, there may be a secondary bacterial infection; this bacterial infection will prolong the symptoms and cause the mucus to thicken and possibly change colour. The runny nose may change to a blocked nose, with thick mucus or catarrh.

By this stage the general symptoms of the cold, the shivering and aches and pains, will have subsided.

What complications might occur?

Colds are self-limiting and common infections, which usually resolve themselves with few or no complicating features. However, they are more serious infections for certain groups of people: the very young, the very old, and those whose immune systemsmay be weakened. In these individuals, a cold can move from the upper airway to the lower airway and lungs; bronchitis or pneumonia may then develop. These are more serious infections and will need the attention of a doctor.

Signs that a cold is developing into something more serious would include a chesty or 'productive' cough (i.e. a cough where the person is bringing up phlegm), especially if that phlegm is discoloured; or earache, if the infection has travelled to the ears.

A bacterial infection may affect the middle ear as a consequence of the original viral infection. There is a small passageway from the nose into the middle part of the ear (the Eustachian tube) which normally regulates the air pressure in the middle ear; this tube can allow an infection to move from the nose into the ear. There may be subsequent symptoms of pain or aching in the ear, and dizziness, which need to be seen by the family doctor for treatment as antibiotics may be necessary.

An infection in the lungs causes the small air tubes deep inside the lungs to swell, and reduces the diameter of the tubes, making breathing more difficult. As these tubes are all lined with mucus-producing tissue, extra fluid will be produced, which may be thick and sticky, and so the air tubes become further obstructed. These infections are serious in people whose general condition is frail (as in the very old) or who have immune systems which are less capable of fighting infection (e.g. the very young).

Infections of the sinuses can last for a long period of time without fully returning to normal. Pain and aching around the eyes may persist, and the condition can flare up from time to time producing pronounced pain and discomfort.

How can I treat a cold?

If you have a cold, there is a lot that you can do to treat it yourself. The attention of a doctor is only needed if more serious symptoms develop.

The body needs to be allowed to fight the infection. One important way to do this is to take plenty of rest; keep warm in bed and avoid strenuous physical exertion if you can. This will allow the immune system to recover sufficiently to attack the invading virus.

Fighting infections takes energy, and energy is mainly obtained from food. Therefore it is important that you continue to eat a healthy diet. Food will help to speed up recovery, especially nourishing foods like fruit and vegetables - not only do they provide calories for energy but also vitamins and essential nutrients.

If it is not possible to take foods by mouth, then energy rich drinks should be taken to compensate. Keeping up a good fluid intake is important; if you become dehydrated, the mucus being produced in your nose and lungs will be thicker, stickier and a greater obstruction to the breathing. Coughing phlegm from the lungs will be made more difficult, and the consequences could be a more severe chest infection. Drinking lots of liquids will help to keep mucus more watery and easier to cough from the lungs.

Treat the symptoms
The symptoms of a cold, the shivering, muscle aches, joint pains, headaches, and runny nose, are very troublesome and can be relieved effectively with remedies available from Pharmacy2U, including simple painkillers for the aches and pains, decongestants for the blocked or runny nose, and cough mixtures if a cough is present.

What treatments are available for me to purchase?

There are no treatments available that will 'cure' or shorten the length of a cold. Treatments are designed to reduce the symptoms of the cold and are categorised below according to the symptom they treat.

Headache, aches and pains and fever
General aches and pains can be treated with a mild painkiller. Aspirin and paracetamol will also help to reduce a raised temperature. For more information see the section on Pain.

To see the full range of painkillers available from Pharmacy2U Click here.

Runny/blocked nose
Decongestants will help to reduce the amount of mucus produced, thus easing nasal congestion. Decongestants taken by mouth include pseudoephedrine, phenylpropanolamine and ephedrine, and are included in products such as Sudafed and Sinutab. These decongestants should not be used by people suffering from high blood pressure, heart disease, hyperthyroidism, glaucoma, diabetes, or enlarged prostate.

Some of these products also contain an antihistamine which may have a drying effect. Most of these antihistamines also cause drowsiness and should be used with caution if driving.

Decongestants applied directly to the nose in the form of sprays or nose drops are often more effective than oral decongestants; they are also safe to use in some cases when oral decongestants are not. However, they should not be used continuously for more than 5-7 days, to prevent a 'rebound' congestion upon stopping.

Coughs may either be dry, in which no phlegm is present or chesty (productive), in which there is phlegm. There are cough mixtures available to treat either type. For more information see the section on Coughs.

Sore throats
Soothing or numbing treatments are available. For more information see the section on sore throats.

Multiple ingredient remedies
There are many cold remedies available which contain many or all of the treatments described above; they may be convenient to take but they are not always the best option. They may contain ingredients which are unnecessary, e.g. a pain killer when there is no pain. They may have an ingredient which is not appropriate, e.g. a cough suppressant when the cough may be a productive cough.

If more than one product is used, care should be taken that similar ingredients are not included. This is particularly important for products containing paracetamol, overdose of which is very dangerous.

Preventing colds
The viruses which cause colds are spread from person to person through sneezing, coughing and personal contact. Colds may also be caught from cups, towels, and telephones, which have been used by infected people. Avoiding such contact will reduce the likelihood of becoming infected.

There are around 200 different cold viruses and, although previous infections may produce immunity to some, there will always be new viruses to cause further infections.

Resistance to cold viruses can be improved by remaining generally healthy. Emotional stress, fatigue, poor diet and smoking can all increase your chances of catching colds.

It is believed that vitamin C and zinc may have some benefit in the prevention of colds -however this has not been medically proven.

What treatments are available from my doctor?

Colds are caused by viruses and there are no 'cures' available from your doctor. Normally it will not be necessary to see your doctor unless the infection has travelled to the chest or ears, or your overall condition is worsening. If a secondary bacterial infection takes hold, your doctor may prescribe antibiotics; however, these will have no effect on the virus which originally caused the cold.

What additional investigations might be needed?

Additional investigations are only likely to be needed if the cold is developing into something more serious, e.g. an ear infection or a chest infection. Samples of phlegm coughed up from the chest would be needed for further analysis, to determine the best course of action to treat the problem.

Any other information I should have?

Colds are self-limiting infections, that will usually get better with simple self-treatment and will not normally require the attention of a doctor. If you are unsure about the way to treat your cold, please consult the Pharmacy2U pharmacist.