What is the recommended treatment for a patient with verruca vulgaris (common wart)?

Treatment of Verruca Vulgaris (Common Warts)

Start with topical salicylic acid 15-40% as first-line therapy for 3-6 months, and if this fails or is not tolerated, proceed to cryotherapy with liquid nitrogen every 1-2 weeks. 1, 2

First-Line Treatment: Salicylic Acid

• Apply salicylic acid 15-40% topical paint or ointment after paring down the wart to remove excess keratin, which improves penetration to the lower epidermis. 1, 2
• Continue treatment for up to 3-6 months before considering it a failure—this extended duration is necessary as most warts respond within this timeframe. 1, 2
• The paring or debridement should be done carefully to avoid damaging surrounding skin, as trauma can spread the infection through autoinoculation. 2

Second-Line Treatment: Cryotherapy

• If salicylic acid fails after 3 months or is not tolerated, use cryotherapy with liquid nitrogen applied every 1-2 weeks, which achieves 63-88% efficacy for wart clearance. 1, 2
• Cryotherapy is relatively inexpensive, does not require anesthesia, and does not result in scarring if performed properly, though most patients experience moderate pain during and after the procedure. 1
• Substantial training is required for proper technique to control the depth of freeze and prevent scarring, which is particularly important on functional areas like the hands or flexor surfaces. 3, 2
• Recurrence rates with cryotherapy range from 21-39% of patients. 1

Location-Specific Considerations

• For warts on functional areas (such as flexor surfaces of fingers or weight-bearing areas of feet), aggressive destructive treatments risk scarring that could impair function, so conservative approaches are preferred initially. 2
• For facial plane warts, photodynamic therapy (PDT) with reduced concentration of aminolevulinic acid (ALA) from 20% to 10% can maintain efficacy while reducing the chance of post-treatment hyperpigmentation. 1
• Heavily keratinized warts may not respond as well as those on moist mucosal surfaces to topical therapies. 1

Third-Line Options for Refractory Cases

If both salicylic acid and cryotherapy fail after 3-6 months of appropriate treatment, consider these alternatives:

• Intralesional 5-fluorouracil (5-FU) 4%: In a double-blinded RCT, 65% of warts cleared with up to four weekly injections (combined with lidocaine and adrenaline) compared with 35% in the placebo group. 1
• Topical 5-FU 5% cream: Applied once daily for 4 weeks under occlusion, cleared 60% of hand or foot warts compared with 17% with placebo, though it can cause inflammation and pigmentary changes. 1
• Dithranol 2% cream: Showed a 56% cure rate compared to 26% with salicylic acid/lactic acid combination in one RCT, with case series reporting 60-70% patient cure rates. 1
• Photodynamic therapy (PDT): Using ALA-PDT, 75% of plantar warts completely resolved compared with 23% in the placebo group when combined with urea 10% and salicylic acid 10% ointment pretreatment. 1
• Surgical excision with electrocautery or curettage: Reserved for extensive or refractory disease, with one randomized trial demonstrating 93% efficacy but 29% recurrence rate. 1, 2

Alternative Agents (Lower Evidence Quality)

• Glutaraldehyde 10% paint: Reported as equivalent to salicylic acid paint in plantar warts with a 72% cure rate in resistant cases, but should be used with caution due to risk of deep necrosis at concentrations >10%. 1
• Formaldehyde 3% soaks: Reported 80% cure rate in an open study of 646 children with plantar warts, though formaldehyde is allergenic and no randomized studies have been completed. 1

Critical Warnings and Pitfalls

• All treatments remove visible warts but do not eradicate HPV infection, and recurrence rates are high (21-39%) with all treatment modalities regardless of the approach used. 1, 3, 2
• Avoid aggressive destructive treatments on functional areas (hands, feet, flexor surfaces) where scarring could impair function or cause chronic pain syndromes. 2
• Common complications with ablative treatments include persistent hypopigmentation or hyperpigmentation and depressed or hypertrophic scars. 3, 4
• Rare but serious complications include disabling chronic pain syndromes such as vulvodynia or hyperesthesia of the treatment site. 3
• Do not use podophyllin or podophyllotoxin for cutaneous warts—these are appropriate only for anogenital warts, as penetration of the thick, cornified layer of cutaneous warts is poor. 1

Expected Outcomes

• Most warts respond within 3 months of appropriate therapy, with cure rates generally lower for hand warts in adults compared to children. 2
• Children often experience spontaneous resolution within 1-2 years without treatment. 2
• In placebo-controlled studies, genital warts (and by extension, other warts) have cleared spontaneously without treatment in 20-30% of patients within 3 months. 1