Treating Large Cold Sores: OTC, Home Remedies, and When to See a Doctor

Immediate Management for a Large Cold Sore (Herpes Labialis)

1. Antiviral Therapy (Most Effective)

• Oral (prescription): Valacyclovir 2g BID x 1 day (best), famciclovir, acyclovir. Start at prodrome (tingle).
• Topical OTC: Docosanol 10% (Abreva) – modest benefit if applied early.
• Topical Rx: Acyclovir 5%, penciclovir 1% – q3-4h x 5 days.

2. Symptom Relief

• Pain: Ibuprofen, acetaminophen; topical lidocaine/benzocaine.
• Swelling: Cold compress (ice wrapped) 10 min/hour.
• Moisture: Petroleum jelly or lip balm – prevents cracking.
• Lysine (oral/topical): Limited evidence; safe to try.

3. Avoid Triggers

• UV exposure → use lip balm SPF 30+.
• Stress, fatigue, illness, hormonal changes.
• Trauma to lips.

4. When to See a Doctor

• Lesion >10–14 days without improvement.
• Frequent recurrences (>6/yr) → suppressive antiviral therapy.
• Immunocompromised, near eyes, widespread.
• Fever, difficulty swallowing, dehydration.

Prevention of Spread

• No kissing, sharing utensils/towels while active.
• Wash hands after touching.