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Mizuho Morrison, DO, Brittney DeClerck, MD, and Matthieu DeClerck, MD

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Viral warts are common in children and most resolve spontaneously without treatment. Salicylic acid with regular paring and occlusion is the preferred treatment for cutaneous viral warts. Cryotherapy in combination with salicylic acid is recommended as a second line treatment.



  • Warts are caused by HPV and therefore caution should be used by patient and provider to not further spread the virus with treatment.
  • Certain types of skin cancer and precancerous lesions can resemble warts.
  • Avoid cryotherapy on the face as this can cause scarring. 
  • Frequent and large numbers of warts can be an indicator of undiagnosed immune deficiency.


  • Warts are viral skin infections caused by HPV (human papillomavirus) which cause hyperproliferation of keratinocytes. 
  • There are >200 types of HPV. Those that cause cervical, anal, and penile cancers are different strains than those that cause warts. 
  • Warts are very common and affect ~15% of the population.

Types of Warts

  • Verruca vulgaris, or the common wart, can occur on any keratinized epithelium (ie: skin).
  • Verruca plana, or flat warts,  are less obvious and commonly occur on the face or legs and are spread by shaving. 
  • Plantar warts occur on the foot and can be painful and grow inward making treatment difficult.
    • Can be differentiated from corns by black specks representing the blood vessels supplying them.
      • Differentiating corns/calluses from plantar warts can be facilitated by paring them down with a scalpel. This is just removal of dead skin and does not require anesthetic.
  • Filiform warts are so named because they have finger-like projections and look like skin tags.

Other Differential Diagnosis Considerations

  • Molluscum contagiosum is caused by the pox virus and has a central dimple/umbilication.
  • Syringoma are benign tumors of the sweat ducts and can be confused for flat warts.
    • Most commonly seen around the eyes and eyelids
  • Actinic Keratosis, Seborrheic Keratosis, & Squamous Cell Cancer
    • Many of these can resemble warts and may require a biopsy to differentiate.


  • Transmission is generally from direct contact, however the virus can also be acquired from fomites. This is most evident in plantar warts from public pools and locker room floors.


  • Most warts in immunocompetent patients will resolve within several years.
  • The first line treatment is salicylic acid, but it requires multiple treatments for the wart to resolve.
    • After each treatment, the macerated skin should be abraded away with a tool such as pumice or a nail file. 
    • A small nail clipper can also be used to trim the wart. 
    • These tools should only be used for wart treatment to avoid spreading HPV to other parts of the body. 

Dr. Brittney DeClerck’s Patient Guide to Salicylic Acid Use:

  • Day #1: Wash the area with warm water to soften the skin. Then apply a small amount of salicylic acid, and then cover with an occlusive dressing (ie: duct tape or Moleskin) for 24 hours.
  • Day #2: Remove dressing and macerated skin. Reapply salicylic acid and dressing. Repeat until wart is gone (generally 1-6 weeks).
  • Liquid nitrogen is effective but painful, limiting its utility on children.
    • Generally, several repeat treatments may be necessary. Patients should be referred back to their PCP or dermatologist for follow-up in ~2 weeks.
    • Aim for turning the wart and 1-2 mm of surrounding tissue white. 
    • Freeze for ~12 seconds and then allow 30 seconds of thawing to prevent scarring.
    • Reapply 2-3x per session.
      • Avoid using liquid nitrogen on the face due to possibility of scarring.
  • Dermatologists have various other treatments they use for resistant warts such as cantharidin, trichloroacetic acid, laser, and immune system stimulation with imiquimod, cimetidine, Candidal antigen injections.
  • Flat Warts should generally be managed by a dermatologist because they are harder to remove and often cover a wider surface area. 
  • HPV vaccination may slightly reduce risk and severity of cutaneous warts, but data are not yet clear.



  1. Sterling J, et al. British Association of Dermatologists' guidelines for the management of cutaneous warts 2014. Br J Dermatol. 2014 Oct;171(4):696-712. PMID 25273231
  2. Lynch M, Cliffe J, et al. Management of cutaneous viral warts. BMJ 2014 May;348:g3339 PMID 24865780
  3. Bacelieri R, Johnson S. Cutaneous warts: an evidence-based approach to therapy. Am Fam Physician. 2005 Aug 15;72(4):647-52. PMID 16127954
  4. Goldstein A, Goldstein B.Cutaneous warts (common, plantar, and flat warts). In Ofori AO (Ed.) 2017, UpToDate.

Ian L., Dr -

Body warts can be occluded by non-porous adhesive dressings for a week and they wither . Plantar warts are notoriously persistent but podiatrists seem to be able to concoct paring and paints to reduce their size . A lot of patience is required .

Mike W., MD -

Thx for sharing, Ian!!

Mike W., MD -

On Wed, Aug 5, 2020 at 3:05 PM PDT, Janei Bee <> wrote:
I'd use 5FU in salycilyc acid.
Put a 1/2 drop on wart. Cover with TAPE .. not bandaid. Take off in am. Wash area. .wart literally falls off 8-12 days. No pain. Used on youngest 3 years old. I'd never do anything else.

Mike W., MD -

Thx Janei!

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Urgent Care August 2020 Written Summary 865 KB - PDF

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