What is the best course of treatment for a 25-year-old patient with their first aphthous ulcer (canker sore), accompanied by recently resolved fever, headache, and body aches, and current oral and tongue sores?

Primary Herpetic Gingivostomatitis Treatment

This presentation is consistent with primary herpetic gingivostomatitis (not aphthous ulcers), and oral antiviral therapy with valacyclovir or famciclovir should be initiated immediately, even though the systemic symptoms have resolved, to accelerate healing of the oral lesions and reduce pain. 1

Clinical Distinction: Why This Is NOT Aphthous Ulcers

The clinical presentation strongly suggests primary herpes simplex virus (HSV) infection rather than true aphthous ulcers:

• First episode with prodromal systemic symptoms: The combination of fever, headache, and body aches preceding oral ulcers is characteristic of primary herpetic gingivostomatitis, not recurrent aphthous stomatitis 1
• Age and presentation: A 25-year-old experiencing their "first canker sore" with this severity and systemic symptoms indicates primary HSV infection 1
• Multiple oral and tongue lesions: The distribution pattern described is more consistent with herpetic gingivostomatitis 1

Recommended Treatment Regimen

Oral Antiviral Therapy (Primary Treatment)

For initial primary gingivostomatitis, oral acyclovir is beneficial by reducing time to healing, though the FDA has not formally approved any antiviral agent specifically for initial primary gingivostomatitis 1. Despite this, treatment is warranted based on clinical evidence:

• Valacyclovir: Short-course, high-dose regimen (dosing extrapolated from herpes labialis treatment: 2g twice daily for 1 day) 1
• Famciclovir: 1500 mg once daily for 1 day 1
• Aciclovir: Standard dosing if the above are unavailable 1

These oral antivirals are more beneficial than topical agents for treating HSV episodes 1. The short-course, high-dose regimens offer greater convenience and may improve adherence 1.

Supportive Symptomatic Management

While antivirals address the underlying viral infection, symptomatic relief is essential:

• Topical anesthetics: Benzocaine or lidocaine gel for pain relief 1, 2
• Oral hygiene: Chlorhexidine rinses to prevent secondary bacterial infection 1
• Analgesics/antipyretics: Systemic pain management as needed 1
• Hydration: Critical given oral pain may limit intake 1

Safety Profile

All three oral antivirals (aciclovir, famciclovir, valacyclovir) are generally well tolerated with minimal adverse events in clinical studies 1. Headache is the most common side effect with valacyclovir, while nausea and diarrhea occur at similar rates to placebo 1.

Follow-Up Considerations

• Re-evaluate if no improvement in 7 days: Consider alternative diagnoses or complications 2
• HIV testing: Should be considered in patients with severe or atypical presentations of oral ulcers 1
• Patient education: Explain this is likely primary HSV infection, not recurrent aphthous ulcers, and discuss transmission prevention 1

Critical Pitfall to Avoid

Do not treat this as simple aphthous ulcers with only topical corticosteroids, as this would be inappropriate for active HSV infection and could potentially worsen the condition 1. The systemic prodrome (fever, headache, body aches) is the key distinguishing feature that mandates antiviral therapy 1.