Good or bad? Botulinum toxin in hidradenitis suppurativa

Introduction

Hidradenitis suppurativa (HS), also known as acne inversa, is a chronic dermatological condition, characterized by the occurrence of inflammatory nodules, abscesses, fissures and scaring in typical anatomical locations. The pain, pruritus, suppuration and malodour may significantly affect patients’ quality of life. Various treatment methods are used in its management, including both topical and systemic therapies as well as surgical interventions. Botulinum toxin is a neurotoxin, which injected locally blocks the release of acetylcholine at the nerve terminals, resulting in decreasing muscle spasms and reducing the amount of sweat produced by sweat glands [1]. Injections of botulinum toxin are widely used in dermatology [2] e.g. in treating hyperhidrosis [3], reducing facial wrinkles [4], treating chronic anal fissure [5] and other conditions.

Objective

Our aim was to analyse current evidence on botulinum toxin use in the treatment of HS.

Methods

We performed a review of the literature in Embase and Medline databases, including key words such as “botulinum toxin”, “Botox”, “hidradenitis suppurativa” and “acne inversa”. The search was as broad as possible, including EMTREE and MESH approaches, conducted according to the PRISMA guidelines. The following inclusion criteria were applied: original trials, case reports, case series with botulinum toxin use in HS treatment, with or without any concomitant treatment methods, published in English until May 2022. 18 results were identified in Embase, 1 in Medline and 50 in both databases and given further analysis with additional manual research. 8 articles including 28 patients were included in the final analysis.

Results

The results that matched the inclusion criteria were analysed concerning 1) type of botulinum toxin used, 2) number of units per procedure, 3) HS initial severity and post-procedural results, 4) concomitant therapies, 5) duration of the post-treatment effect, 6) patients’ quality of life. Analysed issues are shown in Table 1 [6–13].

Discussion

Hidradenitis suppurativa, also known as acne inversa, is a chronic inflammatory skin condition that mainly affects areas rich in apocrine sweat glands, such as the armpits, groin, buttocks and the area under the breasts. It often manifests as painful nodules, abscesses, sinuses and scarring. The exact cause of HS is not fully understood, but it is believed to involve a combination of genetic, immunological and environmental factors. Treatment of HS typically involves a multidisciplinary approach tailored to the severity and extent of the disease. Typical treatments include topical therapies, systemic therapies, biologic therapies, surgical interventions and lifestyle modifications. Our review was designed to assess whether botulinum toxin can be effective in the treatment of acne inversa. All reports confirmed a beneficial effect on the course of HS, and consequently on patients’ quality of life. Eight articles covering 28 patients from 2009-2023 were included in the final analysis. Toxin type A (papers by authors Nienstedt et al. [6], Chen et al. [7], Shi et al. [9], Campanati et al. [10], Khoo et al. [11], Feito-Rodríguez et al. [12], O’Reilly et al. [13]) and B were used (research by Grimstad et al. [8]) in the regions such as axillas (research by Nienstedt et al. [6], Chen et al. [7], Grimstad et al. [8], Shi et al. [9], Campanati et al. [10], O’Reilly et al. [13]), groins (articles by Grimstad et al. [8], Shi et al. [9], Campanati et al. [10], Khoo et al. [11], Feito-Rodríguez et al. [12], O’Reilly et al. [13]), genital area (paper by Grimstad et al. [8]), inner thigh (article by Campanati et al. [10]), and areas including gluteal folds, gluteal cleft, and suprapubic area (research by Khoo et al. [11]). Injections at doses of 40 U, 50 U, 100 U, 250 U per therapeutic area were used. In 5 studies, the injections were performed during a single session; in one study, a series of 4 treatments over 3 years were performed.
Depending on the study, during the follow-up period after applying botulinum toxin, visual improvement, reduction in pain and inflammation, increased mobility and accelerated ability to return to physical activity were noted. Patients’ scores in the Dermatology Life Quality Index (DLQI) also showed positive change.
These promising follow-up results suggest that using botulinum toxin in the treatment of HS may bring benefits with no major side effects. In addition, improvement assessed with DLQI indicate a positive impact of the therapy on patients’ overall quality of life, which is a key aspect in managing a chronic disease like HS. Nevertheless, long-term efficacy and safety studies on larger groups of patients are needed in order to investigate botulinum toxin injection effect in the treatment of HS as it seems to be a valuable therapeutic option for patients with this difficult-to-manage disease.

Conclusions

Both botulinum A and B toxins were found to improve the course of HS; also, botulinum toxin managed to reduce the hyperhidrosis present in some patients. No major side effects were noted during the therapy. The effect lasted for several months. Botulinum toxin seems to be a safe and effective treatment in patients with HS, also improving the patients’ quality of life. It can be either used in monotherapy or combination with other methods of treatment.

Funding

No external funding.

Ethical approval

Not applicable.

Conflict of interest

The authors declare no conflict of interest.

References