Treatment of Shingles of the Foot
For shingles affecting the foot, initiate oral valacyclovir 1000 mg three times daily for 7 days (or acyclovir 800 mg five times daily for 7 days) as soon as possible, ideally within 72 hours of rash onset, and continue treatment until all lesions have scabbed. 1, 2, 3
First-Line Antiviral Therapy
Valacyclovir is the preferred oral antiviral for uncomplicated herpes zoster due to its superior convenience (three times daily versus five times daily for acyclovir) and comparable or superior efficacy in reducing acute pain and preventing postherpetic neuralgia. 2, 3, 4
Standard Dosing Regimens:
- Valacyclovir 1000 mg orally three times daily for 7 days (preferred) 2, 3
- Acyclovir 800 mg orally five times daily for 7 days (alternative) 1, 2
- Famciclovir 500 mg orally three times daily for 7 days (alternative) 5
Critical Timing Considerations:
- Treatment should ideally begin within 72 hours of rash onset for maximum effectiveness in reducing acute symptoms and preventing complications. 1, 6
- However, treatment initiated beyond 72 hours may still provide benefit, particularly for pain reduction, so do not withhold antivirals even if presentation is delayed. 4
- Continue treatment until all lesions have scabbed, which is the key clinical endpoint—not an arbitrary 7-day duration. 1, 2
When to Escalate to Intravenous Therapy
Switch to intravenous acyclovir 5-10 mg/kg every 8 hours if any of the following develop: 1, 2, 3
- Disseminated disease (lesions beyond the primary dermatome)
- Multi-dermatomal involvement
- Visceral complications
- Severe immunocompromise with complicated disease
- Inability to tolerate oral medications
Continue IV therapy until clinical improvement occurs, then switch to oral therapy to complete the treatment course. 2, 3
Pain Management
For moderate to severe acute pain during the vesicular phase:
- Gabapentin is the first-line neuropathic pain agent, titrating to 2400 mg daily in divided doses. 3
- Consider short-term NSAIDs or acetaminophen for mild pain. 6
- Narcotics may be required for severe acute pain. 6
Adjunctive Corticosteroid Therapy
Corticosteroids provide only modest benefits and are not routinely recommended. 1, 3
- Prednisone (starting at 40 mg daily, tapered over 3 weeks) may be considered as adjunctive therapy in select cases of severe, widespread disease when added to antivirals. 1, 7
- However, corticosteroids do not reduce the incidence of postherpetic neuralgia and carry significant risks, particularly in elderly patients. 7
- Avoid corticosteroids in immunocompromised patients due to increased risk of disseminated infection. 1
Special Considerations for Foot Involvement
While the foot location does not change the fundamental treatment approach, consider:
- Elevation of the affected foot to promote drainage of edema and inflammatory substances. 1
- Keep the skin well hydrated with emollients to prevent dryness and cracking, which is particularly important on weight-bearing surfaces. 1
- Monitor for secondary bacterial infection, as foot lesions may be more prone to contamination.
Common Pitfalls to Avoid
- Do not use topical antiviral therapy—it is substantially less effective than systemic therapy and is not recommended. 1, 3
- Do not delay treatment waiting for laboratory confirmation in typical presentations, as clinical diagnosis is sufficient in immunocompetent patients. 3
- Do not stop treatment at exactly 7 days if lesions have not fully scabbed—continue until complete crusting occurs. 1, 2
- Do not assume treatment is futile if started after 72 hours—delayed initiation may still provide benefit for pain control. 4
Prevention After Recovery
The recombinant zoster vaccine (Shingrix) is recommended for all adults aged 50 years and older, regardless of prior herpes zoster episodes, and should be considered after recovery from the acute episode to prevent future recurrences. 1, 2, 3