Cold sores are small painful blisters around the lips and mouth caused by the herpes simplex virus, most often HSV-1. Once you’ve been infected, the virus stays in the body for life and reactivates from time to time — triggered by stress, sun exposure, fever, hormonal changes, or other illness. At Take Care Clinic on Sukhumvit Soi 13, our English-speaking doctors prescribe antiviral medication that, started early at the tingling stage, can shorten the outbreak by several days and reduce pain. We also help patients with frequent outbreaks set up suppressive therapy to prevent recurrences during important periods such as weddings, travel, or work events.
Get Cold Sore Treatment Today in Bangkok
Same-day appointments at the clinic and rapid hotel visits across central Bangkok. Antivirals are most effective started in the first 24–48 hours.
Phone: +66 62 674 6771
WhatsApp: +66 95 073 5550
Clinic: Take Care Clinic, Sukhumvit Soi 13, Khlong Toei, Watthana, Bangkok 10110
What a Cold Sore Outbreak Looks Like
A typical outbreak progresses through five stages. First is the prodrome: a tingling, itching, or burning sensation at the future blister site, often 12–24 hours before anything is visible. Second is small reddish swelling. Third is the blister stage: one or more fluid-filled vesicles that may coalesce. Fourth is rupture, when the blisters break open and weep, forming the most contagious phase. Fifth is crusting and healing, with the scab falling off over 7–10 days. The entire outbreak from first tingle to full healing typically runs 10–14 days without treatment, shorter with prompt antivirals.
HSV-1 is acquired in childhood by most people through casual oral contact and lifelong infection is the norm. HSV-2 historically caused genital herpes but is now joined by HSV-1 as a frequent cause of genital outbreaks via oral-genital contact. Common reactivation triggers include strong sun exposure (a common cause for travelers in Thailand), fever or other illness, stress and sleep deprivation, hormonal changes, dental work, and minor trauma to the lips. Recurrence patterns vary widely — some people have one outbreak a year, others several a month.
Cold Sore Treatment
Antiviral medication is most effective when started within the first 24–48 hours of symptoms — ideally at the tingling prodrome stage, before the blister fully forms. The standard options are oral acyclovir 400 mg five times daily for 5 days, valacyclovir 2 g twice in one day, or famciclovir 1.5 g as a single dose. Valacyclovir’s one-day course is the most convenient and often the patient’s choice. Started early, these regimens shorten the outbreak by 1–3 days and reduce peak severity; started after the lesion is fully formed they help less. We prescribe and dispense on-site at the consultation.
Topical antivirals (acyclovir 5% cream, penciclovir) provide modest benefit applied at the first sign of tingling, but oral therapy is more effective. Pain relief with paracetamol or ibuprofen helps. Avoid picking or touching the lesion to prevent spreading the virus to fingers, eyes, or other body parts. Sunscreen on the lips during outdoor activity reduces UV-triggered recurrences, particularly important in Bangkok and beach destinations. Patients with frequent recurrences (six or more outbreaks per year) benefit from suppressive therapy — daily low-dose valacyclovir or acyclovir reduces the number of outbreaks by about 75% and is well tolerated long-term.
When to See a Doctor Urgently
Most cold sores are mild and need only the standard antiviral approach. A few situations warrant urgent assessment: very large or severe outbreaks, lesions spreading rapidly beyond the lips, suspected secondary bacterial infection (yellow crusting, increasing redness, fever), eye involvement (eye pain, redness, blurred vision — herpes simplex keratitis is sight-threatening and needs urgent ophthalmology), immunocompromised patients (HIV, chemotherapy, organ transplant) for whom outbreaks can be more severe and systemic, infants and young children with widespread oral lesions, and the first outbreak in someone with no prior cold sore history, which can be more systemic with fever, swollen glands, and general malaise. We arrange same-day assessment for any of these — and via our doctor hotel visit service if travel to the clinic is impractical.
Cold Sore vs Other Mouth Lesions
Not every lip or mouth lesion is a cold sore. Aphthous ulcers (canker sores) appear inside the mouth (cold sores are typically on the lip border), are not caused by herpes, and need different management. Angular cheilitis is cracking at the corners of the mouth, often fungal or nutritional rather than viral. Impetigo is a bacterial skin infection that can mimic cold sores with yellow crusting. Allergic contact dermatitis from lip products causes lip swelling and rash without classic blister stages. We make the distinction at the visit because the treatments differ entirely.
Genital Herpes (HSV-1 or HSV-2)
Cold sores share the same virus family as genital herpes, and HSV-1 from oral contact can cause genital outbreaks too. For patients presenting with genital lesions or wanting type-specific HSV antibody testing alongside other STI screening, we cover that in the broader STD test and STD treatment pages. Treatment principles are similar (antivirals, suppressive therapy for frequent outbreaks); transmission considerations and partner discussion differ from cold sores.
Cold Sore Treatment Costs in Bangkok
A consultation runs 1,500 to 2,500 THB. A single-day valacyclovir course is about 500 to 1,000 THB. A 5-day acyclovir course is 300 to 700 THB. Suppressive therapy for frequent recurrences is around 500 to 1,000 THB per month. Hotel visit fees add 2,000 to 3,000 THB. We provide itemised English-language receipts for travel and expatriate insurance claims.
Get Cold Sore Treatment Today in Bangkok
Antivirals work best started early. Same-day clinic appointments and hotel visits across central Bangkok.
Phone: +66 62 674 6771
WhatsApp: +66 95 073 5550
Frequently Asked Questions
How fast does antiviral medication work?
Started at the tingling prodrome stage, antivirals can sometimes abort the outbreak before a blister fully forms. Started after the lesion is fully developed, they shorten the outbreak by 1–3 days and reduce peak severity but won’t prevent the blister.
Are cold sores contagious?
Yes, particularly during the blister and rupture stages when virus shedding peaks. Avoid kissing, sharing drinks, sharing lip products, and oral sex while a lesion is active. Wash hands after touching the area to avoid spreading to eyes or fingers.
Should I get suppressive therapy?
If you have six or more outbreaks a year, or outbreaks at predictable inconvenient moments (weddings, travel, presentations), suppressive therapy reduces frequency by around 75%. It is well tolerated long-term and can be stopped at any time.
Can sun cause cold sores?
Yes — strong UV exposure is one of the most common triggers, particularly in beach destinations and tropical sun. Lip sunscreen reduces UV-triggered recurrences; reapply often.
Can I get treatment at my hotel?
Yes. Our doctor hotel visit service brings consultation and antiviral medication to your hotel room anywhere in central Bangkok.
References
1. American Academy of Family Physicians. Herpes labialis. Available at: aafp.org.
2. NHS UK. Cold sores. Available at: nhs.uk/conditions/cold-sores.
3. World Health Organization. Herpes simplex virus key facts. Available at: who.int.
4. Centers for Disease Control and Prevention. Genital herpes — STI Treatment Guidelines. Available at: cdc.gov/std/herpes.