What are the treatment options for plantar warts?

Treatment Options for Plantar Warts

Salicylic acid (15-40%) topical preparations are the first-line treatment for plantar warts due to their safety profile, accessibility, and effectiveness. 1, 2

First-Line Treatment Options

• Salicylic acid works by promoting exfoliation of epidermal cells and stimulating host immunity against warts 2
• Available as topical paints or ointments in concentrations of 15-40% for plantar warts 1, 3
• FDA-approved for use in hyperkeratotic skin disorders including verrucae (warts) 4
• Application method:
  • Pare/debride the wart before application to remove excess keratin 1, 2
  • Apply daily after removing the thick keratin layer 2
  • Consider occlusion to improve efficacy 2, 3

Second-Line Treatment Option

• Cryotherapy is recommended as a second-line treatment, applied fortnightly for 3-4 months 1, 2
• More aggressive regimens of both salicylic acid and cryotherapy may be more effective but come with worse side effects 1
• Combination treatments (salicylic acid plus cryotherapy) can be undertaken for resistant warts 1

Alternative Treatments for Resistant Plantar Warts

• Dithranol 1
• 5-Fluorouracil (5-FU) 1
• Formaldehyde (3% solution as daily soaks) 1
• Glutaraldehyde (10% solution) 1
• Hyperthermia (localized heat up to 44°C) 1
• Laser therapy 1
• Photodynamic therapy (PDT) 1
• Podophyllotoxin 1
• Topical immunotherapy 1
• Imiquimod 5% cream (immune response modifier) 5, 6
• Bleomycin (more painful but requires fewer treatment sessions) 7
• Cantharidin-podophyllotoxin-salicylic acid combination (95.8% success rate in one study) 8, 9

Treatment Algorithm

1. Start with salicylic acid 15-40% 1, 2

   • Pare the wart, apply daily, consider occlusion
   • Continue for 3 months

2. If no improvement after 3 months:

   • Switch to cryotherapy (fortnightly for 3-4 months) 1, 2 OR
   • Consider combination therapy (salicylic acid plus cryotherapy) 1

3. For resistant warts:

   • Consider more aggressive regimens of salicylic acid or cryotherapy 1
   • Try alternative treatments like formaldehyde, glutaraldehyde, or cantharidin-podophyllotoxin-salicylic acid combination 1, 8
   • Imiquimod 5% cream may be effective for resistant cases 5, 6
   • Bleomycin can be considered for highly resistant cases (requires fewer sessions but is more painful) 7

Special Considerations

• Plantar warts have lower cure rates than warts at other sites due to thicker cornified layer 1, 2
• Warts in children often resolve spontaneously within 1-2 years; painful treatments should be avoided in young children 1
• For immunosuppressed patients, treatment may not result in cure but can help reduce wart size and functional problems 1

Common Pitfalls and Caveats

• Avoid damaging surrounding skin during paring to prevent spreading the infection 1
• Salicylic acid can cause chemical burns and should not be used in areas of poor healing 3
• Patient compliance with salicylic acid is often poor due to irritation of surrounding skin 3
• Treatment should continue for an adequate duration (3-4 months) before determining failure 2, 3
• Combination treatments may improve efficacy - imiquimod with salicylic acid pads has shown success in resistant cases 6