What are the recommended management options for cutaneous warts?

Management of Cutaneous Warts

First-Line Treatment: Salicylic Acid

Start with topical salicylic acid 15-26% applied daily for 3-4 months, as this has the strongest evidence (Level 1+, Grade A) for treating cutaneous warts and is 16 times more likely to clear warts than placebo. 1, 2

Application Technique

• Soak the wart in warm water for 5-10 minutes before each application to soften the thickened keratin layer 2
• Pare down the wart surface using a disposable emery board, pumice stone, or callus file, removing only the white thickened keratin—stop if you see pinpoint bleeding, as this indicates you've reached the dermal papillae 2
• Discard the paring tool after use or dedicate it solely to the wart to prevent spreading infection 2
• Apply salicylic acid daily after paring, and consider occlusion with a bandage or tape to enhance penetration 1, 2
• Continue treatment for the full 3-4 months before declaring failure—premature discontinuation is a common pitfall 2, 3

Site-Specific Considerations

• For hand warts: Use 15-26% salicylic acid with occlusion; cure rates are significantly higher than for plantar warts 1, 2
• For plantar warts: Use 20-40% preparations after adequate paring; expect lower cure rates (approximately 33%) due to the thicker cornified layer that blocks treatment penetration 3, 4
• For plane (flat) warts: Use lower concentrations (2-10%) or cautious 12-17% paint without occlusion to avoid scarring 2

Second-Line Treatment: Cryotherapy

If salicylic acid fails after 3 months, switch to liquid nitrogen cryotherapy applied every 2-4 weeks for at least 3 months or up to six treatments. 2, 3

Cryotherapy Protocol

• Freeze the wart for 15-30 seconds per treatment and repeat every 2-4 weeks 2
• Expect cure rates of 30-39% for plantar warts and higher rates (up to 70%) for hand warts 3, 5
• More aggressive cryotherapy (longer freeze times) may achieve 65% cure rates but increases pain, blistering, and scarring risk 3
• Avoid cryotherapy in patients with diabetes, impaired circulation, or near cutaneous nerves and tendons 3

Combination Therapy

• Combining salicylic acid with cryotherapy may achieve 86% clearance rates, significantly better than either treatment alone (RR 1.24,95% CI 1.07-1.43) 1, 3, 6, 7
• This approach increases side effects but is appropriate for resistant warts 3

Third-Line Treatments for Recalcitrant Warts

For warts resistant to both salicylic acid and cryotherapy after 3-4 months, consider the following options in order of evidence strength:

Contact Immunotherapy (Level of Evidence B)

• Diphencyprone (DPC) or squaric acid dibutyl ester (SADBE) applied at appropriate strength from twice weekly to every 3 weeks for 3-6 months 2
• DPC achieves 88% complete clearance with a median treatment time of 5 months 3
• Dinitrochlorobenzene showed more than twice the effectiveness of placebo (RR 2.12,95% CI 1.38-3.26) 7

5-Fluorouracil (Level of Evidence 2+, Grade C)

• Topical 5-FU 0.5% combined with 10% salicylic acid shows 63% clearance versus 11% with SA alone 1
• For recalcitrant plantar warts, 5-FU under occlusion achieves 95% clearance after 12 weeks 3
• Causes inflammation and occasionally erosions; hyperpigmentation may occur 1

Intralesional Bleomycin (Level of Evidence C)

• Inject 0.1-1 mg/mL solution into the wart after local anesthesia, with one to three treatments typically needed 2
• Painful during and after treatment; evidence is inconsistent 2, 7

Pulsed Dye Laser (Level of Evidence C)

• Apply after paring and/or salicylic acid pretreatment using 7-10 J/cm², with two to four treatments usually needed 2

Alternative Destructive Agents

• Formaldehyde 3-4% solution as daily 15-20 minute soaks (Level 3, Grade D): reported 80% cure rate in an open study of 646 children, but is allergenic 1, 3
• Glutaraldehyde 10% paint (Level 3, Grade D): equivalent to SA in plantar warts with 72% cure rate, but risk of deep necrosis with repeated application 1, 3
• Dithranol 2% cream (Level 2): 56% cure rate versus 26% with SA/lactic acid combination; 71% clearance of mosaic plantar warts within 10 months 1

Watchful Waiting: A Reasonable Alternative

For immunocompetent patients without functional impairment or significant cosmetic concern, observation for 6 months to 2 years is entirely acceptable. 1, 2

• In children, 65% of warts resolve spontaneously by 2 years and 80% by 4 years 2
• In adults, approximately 30% resolve within 6 months 3
• Consider this approach especially for young children where painful treatments should be avoided 4

Special Populations

Children Under 12 Years

• Salicylic acid 15-40% is the preferred first-line treatment 4
• Limit the treatment area to avoid salicylate toxicity—monitor for tinnitus, nausea, vomiting, hyperventilation, and confusion 4
• Avoid use during varicella (chickenpox) or influenza-like illnesses due to Reye syndrome risk 4
• Proper debridement before each application is essential for efficacy 4

Immunosuppressed Patients

• Warts may be large, extensive, and resistant to treatment 1
• Treatment may not result in cure but can help reduce wart size and associated functional problems 4
• Unusually severe or prolonged warts should prompt consideration of underlying immune deficit 1

Critical Pitfalls to Avoid

• Do not stop treatment prematurely—salicylic acid requires 3-4 months and cryotherapy needs at least 3 months or six treatments before declaring failure 2, 3
• Avoid aggressive paring that damages surrounding normal skin, as this spreads HPV infection to adjacent areas 1, 2, 3
• Do not use multiple destructive modalities simultaneously in initial treatment, as this increases scarring risk without proven benefit 2
• Avoid surgical excision for plantar warts—there are no high-quality studies supporting its use (Level 3, Grade D) and it carries significant scarring risk 3
• Patient compliance is often poor due to surrounding skin irritation and prolonged treatment courses—set realistic expectations 1, 3

Treatment Algorithm Summary

1. Start with salicylic acid 15-26% daily with proper paring for 3-4 months 1, 2
2. If no improvement after 3 months, switch to cryotherapy every 2-4 weeks for 3-4 months 2, 3
3. For resistant cases, combine salicylic acid with cryotherapy 3, 6
4. For recalcitrant warts, consider contact immunotherapy (DPC/SADBE), 5-FU, or other third-line options 2, 3
5. For filiform (finger-like) warts on hands, curettage or hyfrecation may be more appropriate than topical treatments 2