A cold sore starts with a tingle and, within a day or two, turns into a cluster of small blisters, usually on the lip. They are caused by the herpes simplex virus and clear on their own within about 10 days. Treatment started early can shorten that, and a few habits stop you passing the virus on. Here is what works, and the one warning every new parent should know, from the pharmacists at Laois Pharmacy in Portlaoise.
In 30 seconds
- Antiviral cream (aciclovir) works when you start it at the first tingle: five times a day, 4 hours apart. It does not always help once blisters have formed.
- Cold sore patches cover the sore while it heals and cut the risk of spreading it by touch. Make-up can go over them.
- Paracetamol or ibuprofen ease the pain. No aspirin for anyone under 16.
- Cold sores are contagious from the first tingle until the scab has gone. No kissing, no sharing cups, cutlery, towels or lip products.
- Never kiss a baby while you have a cold sore. The virus can be fatal to newborns.
- See a GP if a cold sore has not started to heal in 10 days, is very large or painful, is near the eye, or keeps coming back.
Is it a cold sore?
Cold sores follow a pattern: a tingling, itching or burning feeling on the lip, then within 48 hours one or more small fluid-filled blisters, which burst, weep and crust over into a scab that falls off within about 10 days without a scar. Common triggers are being run down with a cold or flu, strong sunshine, and periods. A blister inside the mouth is more likely a mouth ulcer, and crusty golden-brown patches on a child are more likely impetigo. If you are not sure, show us.
Treatments that work
1. Antiviral cream at the first tingle
Aciclovir cream stops the virus multiplying, so timing is everything. Start it as soon as you feel the tingle, before any blister appears. The NHS and HSE both say it does not always work once blisters have formed. Wash your hands before and after, dab a thin layer on the area five times a day with 4 hours between applications, do not rub, and keep it out of the mouth, nose and eyes. Stop and talk to your doctor if the sore has not healed after 9 days of cream. If your immune system is weakened, get medical advice first. Aciclovir cream is a pharmacy medicine, so ask for it at our counter and we will check it suits you.
2. Cold sore patches
Hydrocolloid patches such as Compeed stick over the sore for up to 12 hours. They protect the skin while it heals, stop you touching the sore, and hide it well enough to take concealer or lipstick on top. Use either the cream or the patch on a sore, not both at once.
3. Pain relief
Paracetamol or ibuprofen ease the pain and swelling. Liquid paracetamol is available for children. Do not give aspirin to anyone under 16. See our paracetamol and ibuprofen dose guide and the child fever guide.
4. Antiviral tablets from a GP
If cold sores are very large, very painful or keep coming back, a GP may prescribe antiviral tablets.
5. A pharmacist consultation under the Common Conditions Service
Cold sores are one of the conditions pharmacists can assess and treat under the HSE Common Conditions Service, for anyone aged 1 month or older. At Laois Pharmacy it is a walk-in private consultation of about 10 minutes. The fee is €35, payable even with a medical card, and where treatment is suitable we supply it on the spot. See our Common Conditions Service page.
Triggers, and how to have fewer cold sores
Once you have the virus it stays in your body for life and flares from time to time. You cannot avoid every trigger, but you can use a lip balm with SPF 15 or higher whenever you are out in the sun, winter included, avoid sunbeds, and keep a tube of antiviral cream at home so you can start it the moment you feel a tingle.
How to stop cold sores spreading
The virus spreads by skin-to-skin contact and by anything that touches the sore. You are contagious from the first tingle until the sore has completely healed, scab included. While you have one:
- wash your hands with soap and water every time you touch the sore or apply cream
- do not kiss anyone, and do not have oral sex until it has fully healed, because you could give your partner genital herpes
- do not share cups, cutlery, towels, razors, lip balm or cold sore cream
- do not touch the sore and then your eyes. The virus can infect the eye
- wash a child’s clothes and face cloths separately if they have a cold sore
Children can usually go to school or childcare with a cold sore if they feel well, but should avoid close contact with other children until it heals.
Babies and pregnancy: the warning that matters
If you are pregnant or breastfeeding and need treatment, aciclovir cream can usually be used, but check with us or your doctor first, and make sure the baby does not touch the treated area.
When to see a GP
- the cold sore has not started to heal within 10 days, or is very large or very painful
- you or your child has swollen, painful gums and sores inside the mouth
- your child has a cold sore on the eyelid or near the eye
- you are pregnant, or you have a weakened immune system
- your cold sores keep coming back, or you are not sure it is a cold sore
Compeed Cold Sore Patch, 15Invisible hydrocolloid patches, up to 12 hours each. Protects the sore and takes make-up on top.
€9.85
Pharmacy medicine. Ask at our counter in Portlaoise or message us on WhatsApp and we will check it suits you. Start it at the first tingle.
An everyday lip balm with the SPF 15 the HSE recommends for sun-triggered cold sores.
€4.45
Higher protection for sunny holidays, skiing and anyone who gets cold sores after sun.
€5.95
Patches and plasters are in our first aid range.
Cold sore starting? Ask us today
Walk in for the Common Conditions Service, or message a photo on WhatsApp and we will tell you what to use and whether it needs a doctor.
Cold sores: common questions
How long does a cold sore last?
Most cold sores heal on their own within about 10 days. They start with a tingle, blister within 48 hours, burst and crust over, and the scab falls off without scarring. Antiviral cream started at the tingle can shorten this.
Does aciclovir cream work once the blister has appeared?
It works when started at the very first tingle, before blisters form. The HSE and NHS both say antiviral creams do not always work after blisters appear. At that stage a patch to protect the sore, plus pain relief, is often the more useful choice.
Are cold sores still contagious when they have scabbed over?
Yes. Cold sores are contagious from the first tingle until the sore has completely healed. Keep up the hand washing and avoid kissing until the scab has gone.
Can I kiss my baby if I have a cold sore?
No. Cold sores can cause neonatal herpes, which can be fatal to newborns. Do not kiss your baby, wash your hands before touching them, cover the sore when breastfeeding, and do not let anyone else with a cold sore kiss your baby.
Can a pharmacist treat cold sores in Ireland?
Yes. Under the HSE Common Conditions Service, pharmacists can assess cold sores in anyone aged 1 month or older and supply treatment where suitable. There is a consultation fee, €35 at Laois Pharmacy, which applies even with a medical card. Pharmacies also sell antiviral creams and patches without a consultation.
Sources
- HSE, Cold sores. www2.hse.ie.
- HSE, Common Conditions Service. www2.hse.ie.
- NHS, Cold sores. nhs.uk.
- NHS, Aciclovir. nhs.uk.
General information for people in Ireland, not a substitute for advice about your own health. Always read the label and the leaflet, and ask our pharmacists or your GP.
