Core Dermatology Diagnoses / CategoriesInfectious

Wart

Author: Faculty Reviewer:

Publish date: Posted on
Last updated: May 11, 2022

Keywords #

wart
verruca vulgaris

Diagnosis #

Warts are benign skin proliferations caused by infection with human papillomavirus (HPV). Certain HPV subtypes tend to have predilection for specific body sites. For example, HPV type 1 tend to infect the solves of the feet, HPV types 2 and 4 infect many epidermal surfaces and HPV types 6 and 11 infect the anogenital area and are considered sexually transmitted infections. Warts are subdivided into common warts (verruca vulgaris), plantar warts, flat warts, and anogenital warts. The diagnosis of warts is usually a clinical diagnosis; however, biopsy can be done if in doubt. Lesions resistant to therapy or concerning for malignancy should be biopsied. Spontaneous remission is common, especially in children. Patients with suppressed immune systems are less likely to experience spontaneous remission.

Key Concepts #
  • Warts are caused by HPV infection of the epithelium.
  • Wart subtypes include common warts (verruca vulgaris), plantar warts, flat warts and anogenital warts.
  • Diagnosis of warts is a clinical diagnosis, but biopsy can be performed if there is concern for malignancy.
  • Spontaneous remission is common.
Epidemiology #

Warts are very common and affect approximately 10% of the population, most commonly affecting children and young adults. Warts are twice as common in Caucasian populations.[1] Immunosuppressed individuals are at a higher risk.

Clinical Features #
  • Lesions have a “verrucous” or hyperkeratotic appearance, often with finger-like projections.
  • Lesions may be a variety of colors, including pink, skin-colored, light brown or darker shades especially in patients with darker skin colors.
  • Paring down overlying hyperkeratotic skin often reveals tiny black or red dots within the lesions due to thrombosed capillaries.
  • Common warts cause an interruption of skin lines and this can be used to diagnose recurrence or incomplete treatment.
Differential Diagnoses #
Diagnostic Workup #

The diagnosis of warts is usually a clinical diagnosis; however, biopsy can be done if in doubt. Paring of overlying skin and dermoscopy can be helpful in making a diagnosis. If biopsy is performed, koilocytes are a characteristic finding.

Treatment #

Treatment of warts is not necessary in many instances and spontaneous resolution is possible. Intervention is warranted when the patient is experiencing discomfort due to physical, functional or emotional factors or when they are immunosuppressed. First line treatment options include salicylic acid or cryotherapy. Cryotherapy may cause hypopigmentation and thus should be used cautiously in patients with darker skin. Some studies have shown cryotherapy to be more effective than salicylic acid, but other studies suggested no difference.[2,3] Plantar warts have lower cure rates than common warts.[2] More refractory warts can be treated with intralesional candida antigen, intralesional bleomycin, topical fluorouracil and topical imiquimod. TCA acid and duct tape have also been shown to have some efficacy in treatment. Surgical removal should be reserved as a last resort due to scarring which can be painful, especially on the soles of the feet. Topical cantharidin can be used as a blistering agent and has the advantage of painless application. Warts often are not fully treated after one treatment and may need to be re-treated after 3-6 weeks. There is some evidence that treatment with quadrivalent HPV vaccine have therapeutic response for treatment of anogenital warts and may also have beneficial effects for other cutaneous warts.[4] Larger and deeper lesions often require multiple treatment sessions and/or modalities.

References #
  1. Al Aboud AM, Nigam PK. Wart. [Updated 2020 Aug 11]. In: StatPearls [Internet]. Treasure Island FL: StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK431047/
  2. Bruggink SC, Gussekloo J, Berger MY, Zaaijer K, Assendelft WJ, de Waal MW, Bavinck JN, Koes BW, Eekhof JA. Cryotherapy with liquid nitrogen versus topical salicylic acid application for cutaneous warts in primary care: randomized controlled trial. CMAJ. 2010 Oct 19;18215:1624-30. doi: 10.1503/cmaj.092194. Epub 2010 Sep 13. PMID: 20837684; PMCID: PMC2952009.
  3. Cockayne S, Hewitt C, Hicks K, Jayakody S, Kang’ombe AR, Stamuli E, Turner G, Thomas K, Curran M, Denby G, Hashmi F, McIntosh C, McLarnon N, Torgerson D, Watt I; EVerT Team. Cryotherapy versus salicylic acid for the treatment of plantar warts verrucae: a randomised controlled trial. BMJ. 2011 Jun 7;342:d3271. doi: 10.1136/bmj.d3271. PMID: 21652750; PMCID: PMC3109952.
  4. Pham, C. T., Juhasz, M., Sung, C. T., & Mesinkovska, N. A. (2020). The human papillomavirus vaccine as a treatment for human papillomavirus–related dysplastic and neoplastic conditions: A literature review. Journal of the American Academy of Dermatology, 82(1), 202–212. https://doi.org/10.1016/j.jaad.2019.04.067
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