👄 Aphthous Ulcer vs Cold Sore Differential Simulator

Where the Lesion Sits Is the First Diagnostic Clue

Placeholder: intraoral mucosa versus the outer lip vermilion border points toward different diagnoses.

• Buccal/tongue: Aphthous site (Placeholder short caption)
• Outer lip: Cold sore site (Placeholder short caption)
• Non-keratinized: Mucosa type (Placeholder short caption)
• Keratinized: Lip skin type (Placeholder short caption)

Placeholder section heading on lesion location

Placeholder: location alone narrows the differential before appearance is even assessed.

Round Ulcer Versus Clustered Vesicles

Placeholder: a single punched-out ulcer looks nothing like a fluid-filled vesicle cluster.

• Round, gray base: Aphthous shape (Placeholder short caption)
• Grouped vesicles: Cold sore shape (Placeholder short caption)
• Erythematous halo: Border (Placeholder short caption)
• Vesicle to crust: Progression (Placeholder short caption)

Placeholder section heading on lesion appearance

Placeholder: surface morphology is the second confirming clue in the exam.

Non-Infectious Ulcer Versus Transmissible Virus

Placeholder: only the viral lesion can spread to other people or body sites.

• None: Aphthous transmission (Placeholder short caption)
• Direct contact: Cold sore transmission (Placeholder short caption)
• Pre-crust phase: Shedding window (Placeholder short caption)
• ~60-70%: Population HSV-1 (Placeholder short caption)

Placeholder section heading on contagiousness

Placeholder: contagion risk changes counseling and isolation advice.

Immune/Trauma Trigger Versus HSV-1 Reactivation

Placeholder: the two lesions arise from entirely different biological mechanisms.

• Stress/trauma: Aphthous trigger (Placeholder short caption)
• HSV-1 reactivation: Cold sore trigger (Placeholder short caption)
• T-cell mediated: Immune role (Placeholder short caption)
• Trigeminal ganglion: Latency site (Placeholder short caption)

Placeholder section heading on underlying cause

Placeholder: cause determines whether antivirals are relevant at all.

Divergent Management Once Diagnosis Is Set

Placeholder: topical steroids help one lesion, antivirals help the other.

• Topical steroid: Aphthous therapy (Placeholder short caption)
• Antiviral cream/pill: Cold sore therapy (Placeholder short caption)
• 7-14 days: Healing time (Placeholder short caption)
• Both can recur: Recurrence (Placeholder short caption)

Placeholder section heading on treatment approach

Placeholder: matching treatment to diagnosis avoids ineffective care.

Placeholder: antivirals do not help aphthous ulcers; steroids do not treat HSV.