👄 Cold Sore Prodrome-to-Blister Timeline Simulator

Prodrome — the Tingling Warning Phase

Nerve signals announce the outbreak hours before any visible skin change.

• 6–24h: Typical onset (before lesion appears)
• Tingle/itch: Sensation (placeholder symptom note)
• Best now: Antiviral window (placeholder treatment note)
• None yet: Visible signs (placeholder skin status)

What happens at the nerve level

Reactivated virus travels along the nerve toward the skin surface.

Starting antivirals at first tingle shortens the outbreak most.

Redness and Bump Formation

Local inflammation produces visible redness and a small raised papule.

• ~1 day: Duration (placeholder timing)
• Red, swollen: Appearance (placeholder visual cue)
• Yes, rising: Contagious? (placeholder risk note)
• Mild-mod: Pain level (placeholder symptom)

Inflammatory response builds

Immune cells and blood flow increase at the reactivation site.

Blister Cluster Eruption

Small fluid-filled vesicles group together over the papule.

• 2–15: Vesicle count (placeholder cluster size)
• ~1–2 days: Duration (placeholder timing)
• Infectious virions: Fluid content (placeholder note)
• Very high: Contagious? (placeholder risk note)

Blister formation mechanics

Viral replication damages epidermal cells, pooling fluid beneath.

Open Ulcer — Peak Contagious Period

Ruptured vesicles merge into a raw, weeping ulcer.

• Peak: Contagious? (placeholder risk note)
• ~1–3 days: Duration (placeholder timing)
• High: Pain level (placeholder symptom)
• Maximal: Viral shedding (placeholder note)

Why this stage spreads virus most

Exposed fluid carries the highest concentration of live virus.

Avoid contact and shared items during this stage.

Crust Formation and Skin Repair

A protective crust seals the wound while new skin forms below.

• ~3–5 days: Duration (placeholder timing)
• Declining: Contagious? (placeholder risk note)
• Low: Scarring risk (placeholder note)
• 7–10 days: Total episode (placeholder duration)

Final repair phase

Crust flakes away as re-epithelialized skin underneath matures.