Examining the Therapeutic Potential of Botulinum Toxin Type A in the Treatment of Keloids

Keloids are a common form of hypertrophic scars that by definition last beyond 6 months and grow beyond the site of initial injury. Keloids are a common complaint from patients in dermatology and cause significant functional impairment due to cosmetic disfigurement, itching and pain. Current treatment modalities include intralesional corticosteroids, chemotherapeutic agents and laser therapy. Initial reports have demonstrated that Botulinum toxin type A may be a viable treatment option for keloids that can reduce keloid size and reduce associated symptoms while having fewer side effects when compared to intralesional corticosteroid injection, which can cause unnatural blood vessel growth or skin thinning. To date, no study has carefully examined the efficacy of Botulinum toxin type A in treating keloids or its mechanistic effects on keloid biology. Our aim in this study is to pursue a rigorous, randomized control trial to assess the potential use Botulinum toxin type A to treat keloids. Efficacy will be objectively be mentioned by change in keloid size after treatment, along with subjective measures of patient satisfaction and symptoms, and finally physician rated scores. Also, samples from three patients will be analyzed in the laboratory setting to determine the underlying molecular mechanism behind the effects of Botulinum toxin type A on keloid biology.

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Key information

Conditions

Keloid Cicatrix Collagen Diseases Connective Tissue Diseases Fibrosis Pathologic Processes Pathological Conditions, Signs and Symptoms Skin and Connective Tissue Diseases

Age range

18 year–80 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Early Phase 1

Primary location

University of California San Diego

San Diego, California, 92122, United States

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

Adults aged 18 to 80
History of keloid scar for at least 12 months
Absence of keloid treatment for past 12 months
Participant must have a keloid scar of at least 4cm in length.
Participants who score at least 8 or higher on the Vancouver Scar Scale
Subjects who score 5 (neither satisfied nor dissatisfied) to 10 (maximally dissatisfied) on the patient subjective score of dissatisfaction with keloid.
Participants must be in stable health, as confirmed by medical history, per investigator judgment
Participants must be able to read, sign, and understand the informed consent
Participants must be willing to avoid any other treatments to the keloid that will be treated including corticosteroid injections, surgical excision, chemotherapeutic injection, lasers, light-based therapy, radiation therapy, cryotherapy, or pressure therapy, during the study period.

Exclusion criteria

Pregnant women
Keloids on face, neck or scalp
History of hypersensitivity to botulinum toxin
Ongoing or planned treatment with chemotherapy, radiation, isotretinoin, cytokine-based immunotherapies
Any planned surgery during study period
Known diagnosis of insulin dependent diabetes mellitus
Patients being treating with dupilumab for any indication
Patients taking aminoglycoside antibiotics
Patients with pre-existing neuromuscular disorders
Patients with infection around potential injection sites

Treatment and study plan

Botulinum Toxin Type A

Drug

Participants will receive Botulinum toxin type A 5 units / cm3 with injections of 0.2mL spaced evenly 1cm apart within the treatment area (half of the keloid). Each treatment will consist of a maximum of 2 mL (10 injection sites, 50 unit total) of the study drug. Patients will undergo 3 treatments, 6 weeks apart.

Vehicle

Drug

Participants will receive saline injections of 0.2mL spaced evenly 1cm apart within the placebo area (half of the keloid). Each treatment will consist of a maximum of 2 mL (10 injection sites) of the vehicle control (saline). Patients will undergo 3 treatments, 6 weeks apart.

Other names: vehicle control (saline)

Primary outcomes

Change in Keloid volume

Time frame: Measurements obtained at 0 and 24 weeks.

Keloid volume will be measured using the high resolution 3D imaging system (Cherry Imaging platform)

Sponsors and collaborators

Lead sponsor

University of California, San Diego

Other

Registry information

Important dates

Study start: 2022
Primary completion: 2023
Study completion: 2023
First posted: Apr 15, 2022
Registry last updated: Nov 6, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

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