What is the appropriate diagnosis and treatment plan for a healthy 32‑year‑old man with a solitary cutaneous verruca vulgaris on the neck persisting for six months without concerning features?

Management of a 6-Month Persistent Neck Wart in a 32-Year-Old Male

Diagnosis

This is verruca vulgaris (common wart) caused by human papillomavirus (HPV) infection, and the 6-month duration indicates it has passed the typical spontaneous resolution window, warranting active treatment. 1

• Approximately 30% of common warts spontaneously regress within 6 months, and 60% within 2 years, but this lesion has persisted beyond the initial resolution period 1
• The neck location requires careful treatment selection to minimize scarring risk, as this is a cosmetically sensitive area 1

First-Line Treatment Recommendation

Start with topical salicylic acid 15-26% applied daily for 3-4 months after gentle paring of the wart surface. 1, 2

Application technique:

• Pare down the wart gently before each application to remove the thickened keratin layer, which blocks treatment penetration 1, 2
• Apply salicylic acid daily with occlusion (covering with a bandage) if possible to enhance effectiveness 1, 2
• Continue treatment for the full 3-4 months before declaring failure 1, 2

Important caveats for neck location:

• Use lower concentrations (12-17%) without occlusion if irritation occurs, as the neck skin is more sensitive than hands or feet 1
• Avoid aggressive paring that damages surrounding skin, as this can spread HPV infection to adjacent areas 1
• Destructive agents should be used with extreme care on the neck to prevent scarring 1

Second-Line Treatment if Salicylic Acid Fails

If salicylic acid fails after 3-4 months, proceed to cryotherapy with liquid nitrogen applied every 2-4 weeks for at least 3 months. 1, 2

• Freeze the wart for 15-30 seconds per treatment session 1, 2
• Use gentler freeze technique on the neck compared to hands or feet to minimize scarring risk 1
• Repeat treatments every 2-4 weeks for a minimum of 3 months or up to six treatments before declaring failure 1, 2

Third-Line Options for Recalcitrant Cases

For warts resistant to both salicylic acid and cryotherapy, consider contact immunotherapy with diphencyprone (DPC) or squaric acid dibutyl ester (SADBE). 1, 2

• Apply at appropriate strength from twice weekly to every 3 weeks for 3-6 months 1, 2
• This approach has 88% complete clearance rates with median treatment time of 5 months 3

Alternative third-line options:

• Intralesional bleomycin (0.1-1 mg/mL) injected after local anesthesia, though this is painful and requires 1-3 treatments 1, 2
• Pulsed dye laser (7-10 J/cm²) after paring, requiring 2-4 treatments 1, 2
• Topical imiquimod 5% cream applied twice daily for up to 6 months 1

Special Considerations for Neck Location

For filiform (finger-like) warts on the neck, curettage or hyfrecation may be more appropriate than topical treatments. 1, 2

• Surgical excision with adequate margins is effective but should be reserved for lesions that fail conservative treatment to avoid unnecessary scarring 4
• The neck is a cosmetically sensitive area where scarring from aggressive treatment can be more problematic than the wart itself 1

Critical Pitfalls to Avoid

• Do not stop treatment prematurely: Salicylic acid requires a full 3-4 months and cryotherapy needs at least 3 months or six treatments before declaring failure 1, 2
• Avoid multiple destructive modalities simultaneously: This increases scarring risk without proven benefit, particularly important on the neck 2
• Do not use aggressive paring: Damaging surrounding skin spreads HPV infection to adjacent areas 1
• Avoid overly aggressive cryotherapy on the neck: While more aggressive freezing may improve efficacy, it significantly increases pain, blistering, and scarring risk in this cosmetically sensitive area 1, 3

When to Refer

Refer to dermatology if:

• The lesion persists beyond 2-3 weeks of appropriate treatment 5
• Red flag features develop (progressive growth, ulceration, bleeding, size >5mm) 5
• Diagnostic uncertainty exists 5
• The patient is immunosuppressed, as warts in these patients are often intractable to standard therapy 1, 6