Anatom3DCold sores (herpes simplex)
Herpes labialis · Opar (herpes simplex)
What it is
Herpes simplex type 1 hides in the trigeminal nerve and flares as blisters on the lip with stress, sun or illness.
Symptoms & signs
- Tingling or burning before the sore
- a cluster of small blisters on the lip
- weeping, then crusting
- lasts 7–10 days
- the first attack can cause fever and mouth ulcers
🚩 Get help if…
- call 112 / 911 now Fever with confusion, strange behaviour or a seizure
- see a doctor soon Painful red eye or blurred vision with a sore
- see a doctor soon Sores spreading over eczema skin or in a newborn
- see a doctor soon Sores lasting over 2 weeks or with a weak immune system
Where it strikes
Medical treatment
- Aciclovir cream at the first tingle
- oral valaciclovir 2 g twice in one day
- daily suppressive antivirals for frequent attacks
- urgent care if the eye is involved or for eczema herpeticum
Natural & lifestyle
- Sunscreen lip balm (sun triggers attacks)
- no kissing or sharing cups while blisters are present
- manage stress and sleep
Emerging & experimental
- Therapeutic herpes vaccines
- gene editing to cut out the sleeping virus (preclinical)
- pritelivir
Alternative, off-label & anecdotal
Approaches used outside the guidelines, with what their supporters report and what testing has found so far.
- L-lysine supplements — trials disagree; high doses may cut recurrences mixed evidence
- Lemon balm (Melissa) cream — small trials shorten attacks early / small studies
- Propolis ointment — small trials as good as aciclovir early / small studies
- Ice, toothpaste and tea bags — anecdotal anecdotal / traditional
ICD codes
- ICD-10 B00.1
- ICD-11 1F00.01 Herpes simplex labialis