What treatment options are available for a 21-year-old patient with a viral skin wart caused by Human Papillomavirus (HPV)?

HPV and Viral Skin Warts: Patient Education Guide

What Are Skin Warts?

Skin warts are benign (non-cancerous) growths caused by the human papillomavirus (HPV), which infects the outer layer of your skin through small areas of trauma or breaks in the skin. 1

• Over 150 different types of HPV exist, with most common skin warts caused by HPV types 1,2,4,27, or 57 1
• These HPV types that cause skin warts are completely different from the types that cause genital warts or cancer - they are low-risk types that do not lead to cancer 2
• Warts spread through direct contact with the virus, either from touching your own warts (autoinoculation) or from contaminated surfaces like communal showers 3

Natural Course Without Treatment

Approximately 30% of warts resolve spontaneously within 6 months in healthy individuals, as your immune system naturally clears the infection over time. 4, 5

• If left untreated, warts may remain unchanged, increase in size or number, or resolve on their own within months to years 1
• Watchful waiting is a reasonable option for new warts, particularly if they are not causing symptoms 4
• The decision to treat depends on whether the wart causes discomfort, interferes with function, or creates cosmetic concerns 1

First-Line Treatment: Salicylic Acid

Salicylic acid (10-26% concentration) is the recommended first-line treatment for common skin warts, with cure rates of approximately 49% and the strongest evidence base. 1

How to Apply Salicylic Acid:

• Soak the wart in warm water for 5-10 minutes, then gently pare down or file the wart surface before each application - this removes the thick keratin layer that blocks treatment penetration 4, 1
• Apply the salicylic acid paint or gel directly to the wart, avoiding surrounding normal skin 1
• Be careful not to damage surrounding healthy skin during paring, as this can spread the HPV infection to adjacent areas 4, 1
• Apply daily and continue treatment for at least 3-4 months before considering it a failure 4
• Available over-the-counter in paints (10-26%), plasters (40%), or ointments (50%) 1

Second-Line Treatment: Cryotherapy

If salicylic acid fails after 3-4 months or is not tolerated, cryotherapy (freezing with liquid nitrogen) is the recommended next step, with efficacy rates of 63-88%. 1, 4

• Applied by a healthcare provider every 1-2 weeks 1, 4
• Continue cryotherapy for a minimum of 3-4 months before declaring treatment failure 4
• Expect moderate pain during and after the procedure, followed by blistering and necrosis 1
• Does not cause scarring when performed properly 1, 4
• Recurrence occurs in 21-39% of cases due to reactivation of subclinical HPV infection, not reinfection 1, 4

Third-Line Treatment: Surgical Removal

For warts that fail both salicylic acid and cryotherapy, or for large clusters of warts, surgical removal via tangential excision, curettage, or electrosurgery offers 93% efficacy in a single visit. 4, 5

• Requires local anesthesia and creates a wound extending only into the upper dermis 1, 4
• Particularly beneficial when you have a large number or area of warts 1, 5
• Recurrence rate is 29% 4, 5

Important Facts About Treatment

No treatment eliminates the HPV virus from your skin - all treatments only remove visible warts, which is why recurrence is common (approximately 30%) regardless of which method is used. 2, 4

• Recurrence is due to reactivation of subclinical HPV infection already present in surrounding skin, not from reinfection by others 2, 4
• Plantar warts (on the feet) respond most poorly to all treatments due to the thick skin layer preventing adequate treatment penetration 4, 5
• Small warts present for less than 1 year respond better to treatment than older, larger warts 2
• More aggressive treatments increase cure rates but also increase pain and risk of scarring 4, 5

Common Pitfalls to Avoid

Do not use treatments designed for genital warts (like podofilox or imiquimod) on regular skin warts - these are specifically indicated only for genital lesions. 4

• Avoid switching treatments too quickly - give each treatment adequate time (3-4 months minimum) before declaring failure 4
• Do not over-treat with cryotherapy, as this leads to poor outcomes and increased complications 4
• Ensure adequate treatment duration before changing approaches, as premature switching reduces overall success rates 4

When to Seek Medical Evaluation

If the wart changes appearance (becomes pigmented, indurated, fixed, bleeding, or ulcerated), does not respond to standard therapy after 3-4 months, or worsens during treatment, seek medical evaluation to rule out other conditions. 1

• Unusually severe or prolonged warts may indicate underlying immune deficiency and warrant further investigation 1
• Warts need to be distinguished from other skin conditions like corns, calluses, actinic keratoses, or rarely, squamous cell carcinoma 1