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OTC casebook: cold sores


OTC casebook: cold sores


Pharmacist Eve is somewhat surprised to see patient Briony, a woman in her 50s who has not been in for three months, come into the Casebook Pharmacy with a prescription for azathioprine and valaciclovir tablets.

“What’s happened to you, Briony?” asks Eve.

“Well, you know I was getting a lot of cold sores and I was coming in here for something to treat them, but they were getting more frequent and more painful and I was developing other symptoms as well and you referred me to my GP?” says Briony.

“He eventually referred me on to the hospital and after lots of tests they said I had systemic lupus erythematosus (SLE). So that’s what these tablets are for.

“They’ve helped keep things under control but I’m still having some quite nasty attacks from time to time, and I’m still under the hospital. I don’t suppose you know of anything that might help me?”



1.     What is systemic lupus erythematosus (SLE) and what are the causes?

2.     What are the signs and symptoms that might give a pharmacist cause to consider that a patient could be suffering with SLE?

3.     What treatments are available for SLE?

4.     What is the prognosis?

5.     Cold sores are generally a minor ailment for which patients are likely to seek self-treatment initially. What is the cause of the condition and how is it contracted and transmitted?

6.     What are the characteristic features of the condition? What other conditions share diagnostic features with cold sores, and how can they be distinguished from it?

7.     What would make you refer on a patient presenting with cold sores?

8.     What OTC treatments are available?

9.     What additional advice might be given?



1. SLE is an inflammatory multisystem connective tissue disease of unknown cause. It occurs mainly in women.

2. Symptoms and signs are often non-specific, but can include fatigue, which can be severe and debilitating; general malaise and fever; headache; joint and muscle pain; weight loss; cold sores; dry eyes and mouth. In some cases a photosensitive skin rash appears on the cheeks (malar rash), which is characteristic.

3. Treatments include simple analgesics and NSAIDs for pain; plus corticosteroids or azathioprine as a steroid-sparing agent; hydroxychloroquine; and in severe cases, cyclophosphamide. Exposure to sun should be avoided as much as possible and sun screens should be used. Regular aerobic exercise should be recommended.

4. SLE is a serious disease, but the 5 year survival rate is over 90 per cent.

5. Cold sores are caused by the herpes simplex virus type1 (HSV-1). Infection is usually contracted in childhood although it may not manifest clinically for several years – and sometimes not at all - but the virus is never eliminated from the body.

Transmission is through transfer of the virus via saliva to mucous membranes, eg. by kissing. Following attacks the virus regresses to the ganglia of the trigeminal and lumbosacral nerves, where it lies dormant until one of several trigger factors or lowered immunity allows it to break out again.

Trigger factors include the common cold, exposure to the sun, fatigue, stress, exposure to cold weather and wind, trauma around the mouth and hormonal changes associated with the menstrual cycle.

6. Outbreaks of cold sores begin with a prodromal phase of up to 24 hours before any visible signs appear, during which the area on or around the lips begins to tingle, burn or itch.

Erythema then develops, followed by the formation of painful and irritating fluid-filled blisters on the lips and skin around the mouth, which break down into shallow, weeping ulcers within 1–3 days.

The ulcers dry and form crusts, which are shed, and the area heals within a further 2 weeks. The total length of an episode is usually 10–20 days.

Initial outbreaks in children typically manifest as gingivostomastitis, with lesions all over the inside of the mouth and symptoms of systemic infection. Primary infection in adolescents manifests as pharyngitis, with lesions in the throat and symptoms similar to glandular fever.

Conditions with similar features to cold sores include:

·       Mouth ulcers: these occur on the mucous membranes and tongue inside the mouth, not on the outside of the lip and mouth.

·       Chickenpox: vesicles can occur both around the outside and inside the mouth, but they are also widespread on other parts of the body.

·       Impetigo: a bacterial skin infection, more common in children, that usually affects the face but can spread more widely. Lesions are itchy and not confined to the area round the lips, although they may first appear there.

·       Lip cancer: lesions develop slowly and are initially painless.

·       Primary chancre of syphilis: sores can occur on the lip. A single hard ulcer appears, which is painless, followed by swelling and hardening of lymph glands in the neck, then spreading to lymph glands elsewhere in the body.

·       Angular cheilitis: cracks occurring at the corners of the mouth that become inflamed and macerated. It is most common in elderly denture wearers.


7. The following are circumstances for referral:

·       Young children and babies.

·       Sores that do not heal within 14 days.

·       Painless sores.

·       Multiple sores.

·       Systemic symptoms.

·       Frequent attacks.

·       Any eye involvement: HSV in the eyes can cause herpes simplex keratitis, a potentially sight-threatening infection.

·       Atopic and immunocompromised patients.


8. The two main treatments for cold sores are acyclovir and docosanol.

Aciclovir is a synthetic analogue of guanine. Its spectrum of activity is specific to human pathogenic viruses that produce thymidine kinase, of which HSV-1 is one. It is converted by thymidine kinase within viral cells to aciclovir triphosphate, which is then incorporated into viral DNA instead of the deoxyguanosine triphosphate required for DNA synthesis and replication.

It is presented as a 5 per cent cream. It is applied five times daily, at 4-hourly intervals starting, if possible, as soon as prodromal symptoms occur. Treatment can be continued for up to 10 days, if necessary. Aciclovir cream is licensed for use in children and pregnant women.

Evidence of the effectiveness of topical aciclovir has not been convincing, but it may shorten attacks by a day or two if use is begun early enough.1

Docosanol is a saturated fatty acid. It has antiviral activity although its exact mode of action is unknown. In vitro studies have shown that it affects the fusion between the HSV-1 virus and the plasma membrane of the human host cell, inhibiting intracellular uptake and replication.

Docosanol is presented as a 2% cream. It is applied 3-hourly during waking hours (five times daily), for up to a maximum of 10 days. It is licensed for use from age 12 and in pregnant women.

In a clinical trial, docosanol cream produced a reduction in time to healing only marginally greater than placebo.2


Other preparations

Products containing combinations of local anaesthetics, counterirritants, antiseptics and astringents are marketed to reduce discomfort and promote faster healing of sores while the infection takes its course. Some are formulated with alcoholic bases, which may have a drying effect on sores and speed up healing.

The bland cream bases of some products may have a soothing effect. Combination preparations for cold sores are relatively innocuous. Creams can be applied as frequently as necessary, although lotions and gels are limited to three or four applications per day.


9. Additional advice is mainly around preventing the spread of infection. To prevent spread of infection to the eyes patients should wash their hands after applying treatment, and women should be very careful when applying eye makeup if they have a cold sore. People with cold sores should not share towels, face flannels and cutlery with others.

For sufferers whose attacks are triggered by sunlight, an ultraviolet-blocking lip salve or high-factor sunscreen is an effective prophylactic.



Woo SB, Challacombe SJ. Management of recurrent oral herpes simplex infections.

Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2007;103 Suppl:S12.e1-18.

McCarthy JP, Browning WD,Teerlink C, Veit G. Treatment of herpesl abialis: comparison of two OTC drugs and untreated controls. J Esthet Restor Dent. 2012; 24(2):103-9.

Chi CC, et al. Interventions for prevention of herpes simplex labialis (cold sores on the lips) Cochrane Database Syst Rev. 2015; CD010095. doi: 10.1002/14651858.CD010095.pub2.



Picture: FatCamera (iStock) 


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