Ethyl Chloride Spray to Reduce Pain From Local Anesthesia During Mohs Micrographic Surgery

September 12, 2025 updated by: University of California, Davis

Ethyl Chloride Spray to Reduce Pain From Local Anesthesia During Mohs Micrographic Surgery: A Randomized Clinical Trial

Fear of needles is a well-documented issue that affects many patients. This fear may cause significant anxiety in various medical situations, including in the dermatology office 1. If not properly managed, needle phobia can persist, affecting a patient's experience during each visit. This effect may compound and lead to avoidance behaviors that can delay necessary treatments 2. This issue is particularly relevant in a Mohs micrographic surgery (MMS) clinic where each patient experiences several painful needle injections before the day is over.

Ethyl chloride is gaining popularity among dermatologists for its routine use in clinical practice due to its anesthetic and antiseptic properties, especially as a pre-injection agent. Research indicates that cryotherapy or pre-cooling the skin before administering a local anesthetic may offer benefits over topical anesthetics, such as enhanced pain relief, quicker onset, and better patient compliance 3,4. However, to our knowledge, no studies have specifically examined the effectiveness of pre-cooling with ethyl chloride prior to Mohs micrographic surgery. To address this gap, we're conducting a trial aimed at evaluating the impact of pre-cooling with ethyl chloride on pain perception in adult patients undergoing Mohs micrographic surgery with local anesthetic injections.

The trial is a single-center, split-body study. The split-body design will involve dividing the surgical site into two equal halves, with one half (right side relative to patient) designated as the treatment side (receiving ethyl chloride spray prior to lidocaine injection) and the other as the control side (no ethyl chloride spray prior to injection). During the procedure, the participant will be asked to rate the pain associated with the needle injection AND the pain from infiltration of anesthetic from each side of the wound using the visual analog scale (VAS) scoring system (1 = no pain, 10 = most amount of pain possible). The results of the study will help us better understand how to mitigate pain and anxiety for patients requiring MMS.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Estimated)

80

Phase

  • Early Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Locations

  • United States
    • California
      • Sacramento, California, United States, 95816
        • Recruiting
        • UC Davis Dermatology
        • Contact:
          • Daniel Eisen, MD
        • Contact:
          • Salsala Nasim, BS

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • All patients scheduled for MMS with Dr. Daniel Eisen at UC Davis Health Department of Dermatology (3301 C St #1300-1400, Sacramento, CA 95816)
  • Pre-op tumor size at least 1.5 cm (measured on day of procedure)

Exclusion Criteria:

  • Skin disorders related to cold temperatures (i.e. cryoglobulinemia)
  • Anxiolytic medication within past 4 hours
  • Treatment sites around the eyes
  • Pre-op tumor size smaller than 1.5 cm (measured on day of procedure)

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Non-Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Ethyl Chloride Spray

Prior to injection of lidocaine, the investigator will apply ethyl chloride spray, Gebauer's Ethyl Chloride Topical Spray, to the right side of the tumor lesion.

This procedure will be performed for all patients participating in the trial.
Drug: Gebauer's Ethyl Chloride Topical Spray
Prior to injection of lidocaine, the investigator will apply ethyl chloride spray, Gebauer's Ethyl Chloride Topical Spray, continuously for 4 to 10 seconds until the skin turns white. This application will be done from a distance of 8 to 18 cm (3 to 7 inches) to the right side of the tumor lesion.
No Intervention: Control

The investigator will perform no intervention and will continue with the normal standard of care for injecting lidocaine into the left side of the tumor lesion.

This procedure will be performed for all patients participating in the trial.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
VAS pain scores
Time Frame: During the MMS procedure
The primary outcome measure will be the Visual Analog Scale (VAS) pain scores recorded at the time of the initial injection and during the infiltration of anesthetic for each treatment side. Patients will self-report their VAS score from a scale of 0-10. VAS scores will be sorted into 4 categories: 0 = no pain; 1-3 = mild pain; 4-6 = moderate pain; 7-10 = severe pain.
During the MMS procedure
Subject response to "do you prefer precooling with ethyl chloride spray in future Mohs surgery cases?"
Time Frame: Immediately after the MMS procedure
Secondary outcome measure will be study subject's responses to the question: "do you prefer precooling with ethyl chloride spray in future Mohs surgery cases?".
Immediately after the MMS procedure

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

University of California, Davis

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

June 1, 2025

Primary Completion (Estimated)

June 1, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

March 27, 2025

First Submitted That Met QC Criteria

April 7, 2025

First Posted (Actual)

April 9, 2025

Study Record Updates

Last Update Posted (Estimated)

September 18, 2025

Last Update Submitted That Met QC Criteria

September 12, 2025

Last Verified

September 1, 2025

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2251013

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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