Botulinum Toxin Type A for Frontal Hyperhidrosis

Evaluation of the Efficacy of Botulinum Toxin Type A in the Treatment of Frontal Hyperhidrosis

Frontal hyperhidrosis is a form of primary focal hyperhidrosis that significantly impairs patients' quality of life due to excessive visible sweating in the forehead region. Conventional treatment options often show limited efficacy or may be associated with undesirable side effects.

This study aims to evaluate the efficacy and safety of intradermal injections of Botulinum Toxin Type A in patients with primary frontal hyperhidrosis. Clinical outcomes will be assessed using Minor's iodine-starch test, the Hyperhidrosis Disease Severity Scale (HDSS), and patient satisfaction scores. Participants will be followed up one month after treatment to evaluate therapeutic response and potential adverse effects.

Study Overview

• Status: Recruiting
• Conditions: Primary Frontal Hyperhidrosis
• Intervention / Treatment: Drug: Botulinum Toxin Type A

Detailed Description

Primary focal hyperhidrosis is a chronic dermatological disorder characterized by excessive sweating due to overactivity of eccrine sweat glands. Frontal hyperhidrosis is a less common subtype; however, it has a significant psychological and social impact due to the visibility of symptoms and its effect on daily activities and quality of life.

Treatment options include topical antiperspirants such as aluminum chloride, systemic anticholinergic agents such as oxybutynin, and surgical sympathectomy. However, these modalities may be limited by insufficient efficacy or undesirable adverse effects, particularly in frontal hyperhidrosis.

Botulinum toxin type A is a neurotoxin produced by Clostridium botulinum that inhibits the release of acetylcholine at the neuromuscular and neuroglandular junctions, resulting in temporary suppression of eccrine sweat gland activity. Although it is widely used in axillary hyperhidrosis, evidence regarding its use in frontal hyperhidrosis remains limited.

Study Design and Procedures:

This is a prospective interventional clinical study conducted on patients diagnosed with primary frontal hyperhidrosis attending the dermatology clinic at Latakia University Hospital. Written informed consent will be obtained from all participants prior to enrollment.

A detailed medical history will be obtained to exclude patients with neuromuscular disorders, hypersensitivity to botulinum toxin or its components, and active local skin infections.

Baseline assessment of disease severity will be performed using the Hyperhidrosis Disease Severity Scale (HDSS).

The affected frontal area will be identified using Minor's iodine-starch test to confirm active sweating zones. The area will then be mapped into a grid of approximately 2.25 cm² squares with 1 cm spacing between injection points.

Botulinum toxin type A will be reconstituted with 5 ml of 0.9% sodium chloride solution to achieve a concentration of 20 units/ml. Intradermal injections of 2 units per grid point will be administered using a 30-gauge insulin needle.

The total dose will range between 40-80 units depending on the extent of the affected area.

Follow-up evaluation will be performed one month (4 weeks) after treatment.

Clinical outcomes will be assessed using:

• Hyperhidrosis Disease Severity Scale (HDSS)
• Minor's iodine-starch test for assessment of sweating area reduction
• Patient satisfaction questionnaire using a 5-point Likert scale
• Recording of any adverse effects or complications

Outcome measures will include reduction in sweating area, improvement in HDSS score, patient-reported satisfaction, and incidence of adverse events.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Zeinab Y Mohammad, MD; Phone Number: +963937109668; Email: zeinab.y.mohammad@latakia-univ.edu.sy
• Study Contact Backup: Name: Mohamad A Ismaiel, MD, PhD; Phone Number: ‪+963933471500‬; Email: mohamad.ismaiel@latakia-univ.edu.sy

Study Locations

• Syria
  • Latakia, Syria
    • Recruiting
    • Latakia University Hospital
    • Contact: Zeinab Y Mohammad, MD; Phone Number: +963937109668; Email: zeinab.y.mohammad@latakia-univ.edu.sy

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients aged between 18 and 40 years.

Clinically and objectively confirmed primary focal frontal hyperhidrosis, defined by sweat production >50 mg/min and a Hyperhidrosis Disease Severity Scale (HDSS) score ≥3 (moderate to severe).

Inadequate response to topical antiperspirant therapy.

No prior treatment with Botulinum toxin type A within the last 6 months.

No use of any other hyperhidrosis treatment within the last 3 months.

Exclusion Criteria:

• Secondary hyperhidrosis due to systemic conditions such as hyperthyroidism, diabetes mellitus, or neurological disorders.

Neuromuscular disorders including myasthenia gravis or Lambert-Eaton syndrome. Active dermatological conditions or anatomical abnormalities in the frontal region (e.g., infections, inflammation, scars).

Known hypersensitivity to Botulinum toxin or any of its components. Pregnancy or breastfeeding. Use of medications that may interfere with Botulinum toxin activity (e.g., aminoglycosides) within one month prior to treatment.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Botulinum Toxin Type A Group; Participants with primary frontal hyperhidrosis will receive intradermal injections of botulinum toxin type A in the affected frontal area. Injection sites will be identified using Minor's iodine-starch test, followed by standardized grid-based mapping to ensure precise localization and uniform distribution of the toxin across the hyperhidrotic region.

Drug: Botulinum Toxin Type A; Botulinum toxin type A will be reconstituted with 5 mL of 0.9% sodium chloride solution to achieve a concentration of 20 units/mL. Intradermal injections of 2 units per injection point will be administered using a 30-gauge insulin needle. The affected frontal area will be mapped using Minor's iodine-starch test and divided into a grid of approximately 2.25 cm² squares with 1 cm spacing between injection points. The total dose will range from 40 to 80 units depending on the extent of the affected area.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Hyperhidrosis Disease Severity Scale (HDSS) score	Assessment of the change in severity of frontal hyperhidrosis using the Hyperhidrosis Disease Severity Scale (HDSS), a 4-point patient-reported scale. The score will be recorded at baseline prior to treatment and compared to the post-treatment score following intradermal Botulinum toxin type A injection. A reduction in score indicates clinical improvement in disease severity	Baseline and 1 month (4 weeks) after treatment
Change in hyperhidrotic area assessed by Minor's iodine-starch test	Assessment of changes in the frontal hyperhidrotic area using Minor's iodine-starch test. The affected area will be evaluated at baseline prior to treatment and compared with the post-treatment area following intradermal injection of botulinum toxin type A. Reduction in the stained area indicates decreased eccrine sweat gland activity	Baseline and 1 month (4 weeks) after treatment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Patient satisfaction with clinical outcomes of intradermal botulinum toxin type A treatment in primary frontal hyperhidrosis	Satisfaction will be assessed using a 5-point Likert scale ranging from very dissatisfied to very satisfied following intradermal botulinum toxin type A injections. Higher scores indicate greater satisfaction and improved perceived symptom control	1 month (4 weeks) after treatment
Incidence of adverse effects following Botulinum toxin type A injections	Assessment of local and systemic adverse effects following intradermal Botulinum toxin type A injections. Reported complications may include brow ptosis, upper eyelid ptosis, pain at injection site, bruising, headache, and transient weakness. Adverse events will be recorded and classified as present or absent during the 4-week follow-up period	Within 1 month (4 weeks) after treatment

Collaborators and Investigators

• Sponsor: Tishreen University
• Investigators: Principal Investigator: Zeinab Y Mohammad, MD, Latakia university

Publications and helpful links

General Publications

• Campanati A, et al. Treatment of Forehead Hyperhidrosis with Incobotulinum Toxin Type A. Clin Cosmet Investig Dermatol. 2022;15:1-4.
• Böger A, et al. Botulinum toxin for treatment of craniofacial hyperhidrosis. J Neurol. 2000;247(11):857-861.
• Lowe NJ, et al. Treatment of hyperhidrosis with botulinum toxin type A. J Clin Aesthet Dermatol. 2023;16(3):20-25.
• Glaser DA, Hebert AA, Pariser DM, Solish N. Interventions for hyperhidrosis in secondary care. Cochrane Database Syst Rev. 2016;CD010036.
• Grabell DA, Hebert AA. Hyperhidrosis: current management. Clin Cosmet Investig Dermatol. 2017;10:829-833.

Study record dates

Study Major Dates

• Study Start (Actual): November 20, 2025
• Primary Completion (Estimated): July 30, 2026
• Study Completion (Estimated): November 20, 2026

Study Registration Dates

• First Submitted: April 24, 2026
• First Submitted That Met QC Criteria: April 24, 2026
• First Posted (Actual): May 1, 2026

Study Record Updates

• Last Update Posted (Actual): May 1, 2026
• Last Update Submitted That Met QC Criteria: April 24, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: Frontal hyperhidrosis, Primary focal hyperhidrosis, Botulinum toxin type A, Intradermal injection, HDSS, Minor's starch iodine test.
• Additional Relevant MeSH Terms: Amino Acids, Peptides, and Proteins; Proteins; Biological Factors; Hydrolases; Enzymes; Enzymes and Coenzymes; Botulinum Toxins; Metalloendopeptidases; Endopeptidases; Peptide Hydrolases; Metalloproteases; Bacterial Proteins; Bacterial Toxins; Toxins, Biological; Botulinum Toxins, Type A
• Other Study ID Numbers: FH-BTXA-2026-01

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No