Fever Blisters (Cold Sores): Treatment, Symptom Relief, and When to See a Doctor

Fever blisters (herpes labialis) are caused by herpes simplex virus type 1 (HSV‑1). There is no cure—the virus remains latent in trigeminal ganglia—but outbreaks can be shortened and symptoms managed.

First‑Line Self‑Care (Start at Prodrome / First Tingling)

1. Topical antiviral: Docosanol 10% cream (OTC) or prescription penciclovir 1% / acyclovir 5% cream—apply 5×/day × 4–5 days.
2. Oral antiviral (prescription): Valacyclovir 2 g twice daily × 1 day (single‑day regimen) or acyclovir 400 mg 5×/day × 5 days—most effective if started within 6 hrs of prodrome.
3. Cold compress: Ice pack wrapped in cloth, 10–15 min several times daily → reduces pain, swelling, viral replication.
4. OTC analgesics: Ibuprofen 400–600 mg or acetaminophen 500–1000 mg q6h PRN.
5. Protect the lesion: Don’t touch; wash hands after contact; avoid kissing, sharing utensils/towels.
6. Lip care: Petrolatum‑based balm prevents cracking; SPF 15+ lip balm reduces UV‑triggered recurrences.

When to See a Clinician

• First episode (confirm diagnosis, discuss suppression).
• ≥6 outbreaks/year → consider daily suppressive therapy (valacyclovir 500–1000 mg daily).
• Lesions near eyes (herpes keratitis risk), widespread, or >2 weeks duration.
• Immunocompromised (HIV, chemotherapy, biologics).
• Severe pain, secondary bacterial infection (honey‑colored crust, spreading erythema).

Prevention of Recurrences

• Identify triggers: UV exposure, stress, illness, hormonal changes, trauma.
• Daily sunscreen (face + lips).
• Adequate sleep, stress reduction.
• Suppressive antiviral if frequent/severe.