Cold sores

This article explains the cause of cold sores, how to prevent the spread of them and the treatment available for cold sores in New Zealand today.

What is a cold sore?

A cold sore is a blister on the lip caused by the herpes simplex virus. Cold sores generally start with a tingling feeling on the lip and progress through a blister stage to become a sore that gradually heals.

Cold sores are common and can recur throughout life – especially when the immune system is low, you are tired or stressed, or when aggravating factors are present such as dental work, colds or too much sun or wind that irritate the lip.

Cold sores can recur throughout your life because once you’ve been infected with the cold sore herpes simplex virus, it lies dormant in your body and can be reactivated when stressors occur.

Cold sores are very contagious and for this reason it’s never a good idea to share things like lipsticks and chap sticks or water bottles. The incubation period can be up to three weeks.

Cold sores normally last for 7 – 10 days.

What are the signs and symptoms of cold sores?

• Pain, itching or tingling of the lip
• A small, painful red raised area on the lip that becomes a blister
• Blisters which then ooze, break and form a crust
• The crust can break and bleed during the healing process

Mouth infection (herpetic gingivostomatitis) caused by herpes simplex virus can occur in young children aged between one and five years and causes fever, restlessness, excessive dribbling and swollen red gums – if this occurs see a doctor.

Treatment of cold sores

• Normally cold sores will heal themselves, though there are a number of over-the-counter creams sold in pharmacies to help prevent and hasten the healing of cold sores
• See a doctor if cold sores fail to heal, if symptoms are severe or the eyes have become irritated
• Seek medical attention if cold sores recur frequently
• Doctors may prescribe oral anti-viral medication, such as aciclovir, if cold sore infections are frequent
• Teach children with cold sores to wash their hands every time they touch their lip so as not to further spread the infection. Teach them not to pick at the sore

Risks & complications of cold sores

• Cold sores can appear on the fingers, chin or near the nostrils
• Although it’s unusual, cold sores can occur inside your mouth on the gums or on the roof of the mouth
• People with compromised immune systems such as those with cancer or leukaemia have less resistance to cold sores and in these people the virus may cause widespread infection
• Spread of infection to the eyes can cause swollen eyelids and conjunctivitis
• Herpes simplex in the eye can also cause scarring of the corner
• Generally cold sores are caused by herpes simplex type 1 virus, while the herpes simplex type 2 causes genital herpes – though both forms can cause cold sores
• Symptoms of genital herpes include ulceration of the penis or vulva and pain and difficulty passing urine – this requires medical attention
• For mothers, herpes simplex (genital herpes) during pregnancy requires special medical attention

What can I do to prevent cold sores?

• Prevent infection by avoiding skin-to-skin contact – especially when a blister or crust is present and the virus is very contagious
• Avoid triggers such as sunburn or windburn
• Use a sun block or lip balm on the face and lips
• Teach your children not to share cosmetics, straws, water bottles, razors and other personal items
• Teach your children good personal hygiene such as regular hand washing
• A wholesome diet that strengthens the immune system gives children greater immunity against all viruses
• People with recurring cold sores learn to recognise the early tingling sensation on the lip and, by taking quick action with extra vitamins, or special medicated or natural lip preparations, can stop the full progress of the cold sore.

Natural remedies for cold sores

• Some studies have shown the amino acid lysine can help to limit the duration of a cold sore – lysine can be found in foods such as cheese, eggs, fish, red meat or taken as a natural supplement or in a lip cream
• Arginine (another amino acid) rich foods such as chocolate, peanuts, cashew nuts, peas and beers have been found to trigger cold sores – so limit intake if you are prone to cold sores
• Natural health practitioners may also suggest building up the immune system using additional vitamins (vitamins A, C and E) and minerals such as zinc and iron
• Add yoghurt (with acidophilus) to the diet to help build natural immunity
• Pure essential tea tree oil on the infected part of the lip during the early stage of a cold sore can also help – put a few drops on a cotton pad and gently dab the sore
• Another common remedy is the essential oil Melissa or lemon balm which can also be dabbed on the sore.

This is an essential family health reference, covering over 100 common, important, potentially serious and often worrying symptoms and emergencies, such as headaches, chest pain, dizziness, fever, bleeding, tiredness or stress.

This classic bestseller has now been completely revised and updated to include the latest information on how to care for your sick child.

Helpful articles

Cold sores often come hand-in-hand with colds and flu when our immune systems are under attack.  Read more about Colds and Flu in our articles on these topics.