First comes a tingle or burn on the lip, a day before anything shows. Then a cluster of small, painful blisters appears, bursts, crusts over and stays for a week or more. Cold sores (bukhaar ke chhaale, or lab ke chhaale) are among the most common viral infections in the world. They are annoying, and for most healthy people they are harmless.
This guide explains what causes cold sores, how they differ from mouth ulcers, how to ease them, which treatments are available, and how to avoid passing them on.
What are cold sores?
Cold sores are small fluid-filled blisters, usually on or around the lips, caused by the herpes simplex virus (usually type 1). Most people catch the virus in childhood from a kiss or shared utensil. After the first infection the virus stays asleep in the nerves, and it can wake up again from time to time.
Cold sore or mouth ulcer?
- Cold sores start as blisters on the outside edge of the lips or around the mouth. They are contagious.
- Mouth ulcers form inside the mouth, on the cheeks, tongue or gums, and are not contagious. See our guide to mouth ulcers (chaale).
The stages of a cold sore
- Tingling and itching for a day or so, with the skin feeling tight or hot.
- Blisters form, sometimes in a small group.
- Weeping: the blisters burst and leak fluid. This is the most contagious stage.
- Crusting: a yellow-brown scab forms.
- Healing: the scab falls off, usually within seven to ten days, and leaves no scar.
What triggers an outbreak?
- A cold, flu or fever. This is how cold sores got their name.
- Strong sunlight, wind and cold weather.
- Stress, tiredness and lack of sleep.
- Hormonal changes, including periods.
- A cut or injury to the lip, or dental work.
- A weak immune system.
How to ease a cold sore
- Start treatment early, at the first tingle. Antivirals work best at this stage.
- Do not pick or squeeze the blisters. It delays healing and spreads the virus.
- Keep the area clean and dry, and wash your hands before and after touching it.
- Use a cold compress for ten minutes to soothe the soreness.
- Protect the lips from the sun with a lip balm containing sun protection. Read about chapped lips and lip care.
- Avoid acidic or salty foods that sting.
- Take paracetamol or ibuprofen if the pain is bothersome, as the pack says.
Antiviral treatments
Antiviral creams and tablets contain acyclovir (aciclovir). They do not cure the virus, but they can shorten an attack by a day or so if used early.
- Creams and ointments are applied at the first sign of a cold sore, as the pack directs. Options at Khasmart include Zovirax Cream and Acylex Ointment.
- Tablets are used for severe or frequent outbreaks, and need a doctor’s prescription. If you have one, you can upload your prescription.
Lip balms and sun protection help to prevent triggers. Browse our skin care range for lip balm and sunscreen.
How to avoid spreading it
- Avoid kissing and skin contact while a cold sore is present, especially with babies, pregnant women and anyone with a weak immune system or eczema.
- Do not share lip balm, cups, cutlery, towels or razors.
- Wash your hands often, and do not touch your eyes after touching a sore. The virus can infect the eye.
- Avoid oral contact during an outbreak, because herpes can pass to the genitals and the other way round.
- Discard your toothbrush after the outbreak has healed.
When to see a doctor
- The cold sore has not healed after two weeks.
- You get cold sores often, more than a few times a year.
- You have a weak immune system, or you are on chemotherapy or steroids.
- The sores are very large, widespread or very painful.
- You have eczema and the blisters spread across the skin.
- There is any eye pain, redness or blurred vision. This needs urgent care.
- A newborn or young baby has blisters or a fever. This is an emergency.
Frequently asked questions
Can cold sores be cured?
Not at the moment. The virus stays in the body, but outbreaks usually become milder and less frequent with time.
Are cold sores a sexually transmitted infection?
They are caused by the herpes simplex virus, which is usually caught in childhood through everyday contact. It is common and does not carry the stigma that people often fear.
Should I cover a cold sore?
It is better to leave it uncovered so it dries, and keep your hands away from it. Wash your hands after applying any cream.
Does stress really cause cold sores?
Stress, illness and tiredness are common triggers, so looking after sleep and rest can help.
You can order lip care and skin care from Khasmart, with delivery across Pakistan.
This article is for general information and is not a substitute for advice from your doctor or pharmacist. It does not include dosage; always follow the directions on the pack or from your doctor.
