Tingling Lips: When Should You Start Cold Sore Medicine?

Why do cold sores come back?

Cold sores, also called herpes labialis, are usually caused by herpes simplex virus type 1 (HSV-1). After the first infection, the virus remains dormant in a nerve ganglion and can reactivate. A recurrence does not necessarily mean a new infection.

Stress, fever, strong sunlight and irritation around the lips can trigger an outbreak. Small blisters may break, form a crust and heal. Mild recurrences can settle without antiviral medicine.

Recognising symptoms before a blister appears

Tingling, itching, burning or tightness may develop where a cold sore usually appears. These warning symptoms are called the prodrome. Some people have no clear warning.

Not every sore around the lips is herpes. Mouth ulcers and other conditions can look different and need different care. Have a first episode or an unfamiliar-looking lesion assessed.

What is the benefit of starting tablets early?

Oral antiviral medicine limits viral replication. Starting treatment at the first warning symptoms can speed healing and reduce discomfort.

In trials of valacyclovir for recurrent cold sores, treatment started at the earliest symptoms shortened the overall episode by about one day on average compared with placebo. This result comes from early treatment and should not be assumed to apply equally after a large blister has developed.

Treatment does not eliminate the dormant virus, and future outbreaks remain possible. It does not guarantee that a blister will be prevented.

People with troublesome recurrences and a recognisable prodrome can discuss a prescription and a clear plan in advance, so they know when and how to start it.

Choosing a cream or oral medicine

Antiviral creams are applied to the affected area, while tablets are absorbed after swallowing. Timing matters for creams too. Oral treatment may be considered for frequent, severe or persistent episodes; it is not necessary for every mild recurrence.

Tell the prescriber about kidney problems and other medicines. The medicine, dose and duration should follow your individual prescription.

Reducing the risk of spread

From the first tingling until the lesion has completely healed, avoid kissing and oral sex. Do not kiss babies during an outbreak.

Avoid touching or bursting blisters. Wash with soap and water after touching a sore, avoid rubbing your eyes, and do not share lip products. A sun-protective lip product may help people whose outbreaks are triggered by sunlight.

When should you seek care promptly?

Seek prompt medical care for a sore near the eye or associated eye pain, redness or vision changes. Eye symptoms may need an eye specialist.

Arrange an assessment when a sore has not started healing after about ten days, is spreading or very painful, or makes drinking difficult. People with weakened immunity should seek advice early.

At your visit, describe how often outbreaks occur, the first warning symptoms you recognise and how long it takes for blisters to appear. This helps determine whether medication is appropriate and when to start it.