Botulinum Toxin Type A Effective as Add-On for Symptom Control in HS

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Off-label treatment of patients with botulinum toxin type A for patients with hidradenitis suppurativa (HS) is effective as an add-on treatment for symptom control, according to findings from a recent research letter.¹

Noor F. Goandal—from the Department of Dermatology at Zealand University Hospital in Denmark—led the team of investigators in this analysis who published these findings. Goandal and colleagues highlighted that despite the approval of a variety of biological therapies for those with HS, including secukinumab, adalimumab, and bimekizumab, those who suffer from the scarring and inflammatory disease still have a large unmet need for treatment options.

The neurotoxin known as botulinum toxin type A is an inhibitor of cholinergic stimulation to localized eccrine and apocrine glands. Goandal et al. noted that the toxin is commonly used for conditions such as hyperhidrosis.

“Recent findings suggest [botulinum toxin type A] may also reduce inflammation by inhibiting mast cell degranulation, which is increased in HS lesional skin and correlates with disease severity,” Goandal and colleagues wrote. “Despite its potential, [botulinum toxin type A] has not been established as a standard treatment for HS.”^1,2

Impacts of Botulinum Toxin Type A on Hidradenitis Suppurativa

The investigative team conducted a retrospective case series, during which they assessed the off-label botulinum toxin type A in terms of efficacy and satisfaction among patients with HS. The team included all individuals with HS who were given off-label botulinum toxin type A therapy at the Zealand University Hospital dermatology department in the timeframe between 2018 - 2023.

The analysis involved an evaluation of suppuration levels and overall treatment satisfaction through the use of a numeric rating scale (NRS) ranging from 0 - 10. Higher scores on the NRS suggested greater improvement in satisfaction. An NRS score totaling 10 suggested complete suppuration resolution or extreme treatment satisfaction, whereas a score of 5 would suggest moderate improvement.

Demographic information and evaluations of disease severity using the Hurley staging system were all gathered by the investigators throughout the study, as well as additional data on symptoms of the disease such as suppuration and pain. Additionally, the team looked at treatment effects on participants’ daily activities such as education, work, and physical exercise.

A Likert scale was used to help the investigators assess the impact of botulinum toxin type A, involving a range between −3 (suggesting worsening symptoms) to +3 (a highly positive impact) for relief in pain, physical actions, and work or education performance.

There were 8 individuals who took part in this analysis, with the investigators highlighting an average age of 38.25 ± 9.56 years. Overall, those participating reported a high level of satisfaction with botulinum toxin type A as an add-on treatment, given the median satisfaction score of 8.5 (IQR, 6.50–10.0). Among the 6 who were shown to have suppuration prior to treatment, the investigative team noted a moderate reduction, adding that a median score of 6.5 (IQR, 6.00–7.75) was observed.

Additionally, the team reported that 100% of those included as subjects suggested they would recommend the treatment to others with HS. Pain relief following use of botulinum toxin was also shown by the investigators to be moderate, with the team pointing to a median reduction score of 2.50 (IQR, 0.00–3.00).

The effect of the treatment on subjects' performance at work and in educational settings was noted as minimal, with a median score of 0.50 (IQR, 0.00–1.75). Improvements in their physical activity were highlighted by the investigators however, although this was to a lesser extent, with a median score of 1.50 (IQR, 0.75–2.25).

The study suggested consistency between these findings on pain reduction and prior case series on botulinum toxin type A, as well as being consistent with a previous randomized controlled trial assessing botulinum toxin type B for those suffering from HS.

The investigators noted the variance in pain relief outcomes with other HS treatments, highlighting tetracycline as having led to a substantial decrease in pain scores from 6 to 4 on the NRS (P < .05) after 12 weeks. In a similar vein, they noted that adalimumab therapy had led to a 30% reduction in pain (P < .05) among those who maintained a stable tetracycline dosage.

However, they added that there had not been significant relief noted in individuals who could not receive tetracycline. In terms of suppuration, botulinum toxin type A treatment resulted in a moderate reduction.

These improvements observed by the investigative team may be attributed to botulinum toxin’s inhibitory effects on neurogenic inflammation and mast cell degranulation. These likely result in inflammation decreases and diminished formation of abscesses in impacted areas.

“The results from this study set the framework for a future prospective randomized double-blinded placebo-controlled study to further investigate the effect of [botulinum toxin type A] on pain, suppuration, quality of life, and disease severity,” they concluded.¹

References

1. Goandal, N.F., Jemec, G.B.E. and Saunte, D.M.L. (2025), Botulinum toxin type A efficacy on pain and suppuration in hidradenitis suppurativa. J Eur Acad Dermatol Venereol. https://doi.org/10.1111/jdv.20611.

2. Zouboulis CC, Desai N, Emtestam L, Hunger RE, Ioannides D, Juhász I, et al. European S1 guideline for the treatment of hidradenitis suppurativa/acne inversa. J Eur Acad Dermatol Venereol. 2015; 29(4): 619–644.