Herpes Simplex (Cold Sores)

Cold Sore / Fever Blister

Overview

Cold sores are small, painful, fluid-filled blisters caused by herpes simplex virus type 1 (HSV-1), though HSV-2 can also cause them. After initial infection, the virus remains dormant in nerve ganglia and can reactivate periodically, especially during times of stress, illness, sun exposure, or immune suppression. Cold sores are highly contagious.

Key Symptoms

• Tingling, itching, or burning sensation before blisters appear (prodrome)
• Cluster of small, fluid-filled blisters on or around the lips
• Blisters break open and form a shallow ulcer, then crust over
• Pain and tenderness at the blister site
• Healing typically takes 7–14 days
• Recurrences often occur in the same location

Affected Areas

Lips (most common), Around the mouth, Nose, Chin, Inside the mouth

Care Instructions

1. Start antiviral medication (acyclovir, valacyclovir) at the first sign of tingling for best results.
2. Apply topical antiviral cream (docosanol or acyclovir) as directed.
3. Avoid touching, picking, or squeezing blisters to prevent spread.
4. Do not kiss or share utensils, towels, or lip products during an outbreak.
5. Protect lips from sun exposure with SPF lip balm, as UV light can trigger recurrences.
6. See a doctor about daily suppressive antiviral therapy if outbreaks are frequent.

Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice. Always consult a qualified dermatologist for diagnosis and treatment.

Prevalence: Extremely common; approximately 67% of the global population under age 50 has HSV-1 infection