A Trial Examining the Treatment of Common Warts With Combination Liquid Nitrogen (LN2) and Cantharidin


The purpose of the study was to see if liquid nitrogen, a commonly used treatment for warts, is more effective if it is used alone, or if it is more effective if combined with cantharidin, a topical treatment also commonly used for warts (verruca vulgaris).

Full Title of Study: “A Randomized Clinical Trial Examining the Efficacy of Treatment of Cutaneous Verruca Vulgaris in Adult Patients With Combined Liquid Nitrogen Cryotherapy and Topically Applied Cantharidin”

Study Type

  • Study Type: Interventional
  • Study Design
    • Allocation: Randomized
    • Intervention Model: Parallel Assignment
    • Primary Purpose: Treatment
    • Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
  • Study Primary Completion Date: June 2008


  • Drug: Liquid nitrogen and cantharidin
    • Liquid nitrogen applied to wart(s), then cantharidin 1% topical applied afterward.
  • Drug: Liquid nitrogen and topical placebo
    • Liquid nitrogen applied to wart(s), then placebo vehicle applied thereafter.

Arms, Groups and Cohorts

  • Active Comparator: Liquid nitrogen and canthardin
    • Liquid nitrogen applied to wart(s), then cantharidin 1% topical applied afterwards.
  • Placebo Comparator: Liquid nitrogen and placebo
    • Liquid nitrogen applied to wart(s) then placebo vehicle afterwards.

Clinical Trial Outcome Measures

Primary Measures

  • Percentage of common warts cleared
    • Time Frame: 12 weeks
    • Percentage of treated warts cleared with treatment, as measured with dermatoscopic examination, after 12 weeks.

Participating in This Clinical Trial

Inclusion Criteria

1. common warts on non-genital, non-facial skin

2. otherwise healthy

3. between 18-65 and able to give informed consent

4. capable of tolerating treatment

Exclusion Criteria

1. Ill-health

2. Poor tolerance or sensitivity to treatments in study

3. <18 years old; >65 years old

4. verruca plana or condyloma acuminata

5. immunosuppression or immune dysfunction

6. significant peripheral vascular disease

7. significant sensitivity to cold

8. epidermodysplasia verruciformis

9. mosaiform warts or periungual warts

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 65 Years

Are Healthy Volunteers Accepted: Accepts Healthy Volunteers

Investigator Details

  • Lead Sponsor
    • North Idaho Dermatology
  • Provider of Information About this Clinical Study
    • Richard Flygare, Ph.D.; Stephen Craig, M.D., North Idaho Dermatology, TUI University
  • Overall Official(s)
    • Richard A Flygare, PhD, Principal Investigator, TUI University; North Idaho Dermatology


Berth-Jones J, Bourke J, Eglitis H, Harper C, Kirk P, Pavord S, Rajapakse R, Weston P, Wiggins T, Hutchinson PE. Value of a second freeze-thaw cycle in cryotherapy of common warts. Br J Dermatol. 1994 Dec;131(6):883-6.

Guidelines of care for cryosurgery. American Academy of Dermatology Committee on Guidelines of Care. J Am Acad Dermatol. 1994 Oct;31(4):648-53.

Moed L, Shwayder TA, Chang MW. Cantharidin revisited: a blistering defense of an ancient medicine. Arch Dermatol. 2001 Oct;137(10):1357-60. Review.

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