Treatment of hidradenitis suppurativa with intralesional photodynamic therapy with 5-aminolevulinic acid and 630nm laser beam

Topical and Intralesional Therapies for Hidradenitis Suppurativa: A Systematic Literature Review

BACKGROUND AND OBJECTIVE

Topical and intralesional (IL) treatments may be considered the first-line therapy in patients with hidradenitis suppurativa (HS); however, the evidence supporting their use is limited. The aim of our review is to evaluate the efficacy and safety profile of topical and IL treatments in patients with HS.

MATERIALS AND METHODS

We designed a systematic review of the current medical literature available following the PICO(T) method. And including all types of studies (Study type [T]) of individuals with HS of any sex, age, and ethnicity (Population [P]) who received any topical or IL treatment for HS (Intervention [I]) compared to placebo, other treatments, or no treatment at all (Comparator [C]), and reported efficacy and/or safety outcomes (Outcomes [O]). Two outcomes were defined: quality of life and the no. of patients with, at least, one adverse event. The search was conducted in the Cochrane Library, MEDLINE, and Embase databases; study selection was performed based on pre-defined criteria. The risk of bias was determined in each study.

RESULTS

We obtained a total of 11,363 references, 31 of which met the inclusion criteria. These studies included 1143 patients with HS, 62% of whom were women. A total of 10, 8, 6, 2, and 5 studies, respectively, evaluated the use of photodynamic therapy (PDT), glucocorticoids, resorcinol, topical antibiotics, and other interventions. Most articles were case series (n=25), with only five randomized clinical trials (RCTs) and one cohort study. RCTs showed improvement in disease activity with topical clindamycin and botulinum toxin (BTX) vs placebo, and PDT with methylene blue (MB) niosomal vs free MB; however, intralesional triamcinolone acetonide was not superior to placebo. The risk of bias was low in three RCTs and high in two RCTs.

CONCLUSION

The quality of evidence supporting the use of topical, or IL treatments is low. However, it supports the use of topical clindamycin, PDT, and BTX. Well-designed RCTs with standardized outcomes and homogeneous populations of patients and lesions are needed to support decision-making in the routine clinical practice.

Safety and Effectiveness of Percutaneous Ultrasound-Guided Galvanic Current in Tunnels of Patients with Hidradenitis Suppurativa: A Pilot Study

INTRODUCTION

The recurrent nature of hidradenitis suppurativa (HS), even under maintained systemic treatment, makes it necessary to have effective local treatments; however, the response to these therapies is variable (44-81%). The application of galvanic current (GC) has demonstrated its utility in humans in treating lesions structurally similar to those of HS. With this background, the main objective of this study was to evaluate the efficacy and safety of ultrasound-guided percutaneous GC in inflamed and/or draining tunnels of HS.

METHODS

This was an open study (one-way repeated measures design over time). Patients were evaluated at 4 and 12 weeks after receiving GC. A combined clinical response at week 12 (absence of suppuration/inflammation on examination and clinical interview) was considered the principal variable of efficacy. Adverse effects potentially associated with GC were reported by telephone and at each visit.

RESULTS

Twenty-six patients were included, with a male/female ratio of 5:8. The mean age was 35.84 (13.14) years. At 12 weeks after the administration of GC, a complete response was achieved in 77% (20/26) of the treated lesions. No serious adverse effects were observed, and the mean procedural pain assessed by the numeric rating scale was 0.03 (0.2).

CONCLUSION

GC has proven to be effective and well tolerated in inflamed and draining tunnels of patients with HS.

Topical and Intralesional Therapies for Hidradenitis Suppurativa: A Systematic Literature Review

BACKGROUND AND OBJECTIVE

Topical and intralesional (IL) treatments may be considered the first-line therapy in patients with hidradenitis suppurativa (HS); however, the evidence supporting their use is limited. The aim of our review is to evaluate the efficacy and safety profile of topical and IL treatments in patients with HS.

MATERIALS AND METHODS

We designed a systematic review of the current medical literature available following the PICO(T) method. And including all types of studies (Study type [T]) of individuals with HS of any sex, age, and ethnicity (Population [P]) who received any topical or IL treatment for HS (Intervention [I]) compared to placebo, other treatments, or no treatment at all (Comparator [C]), and reported efficacy and/or safety outcomes (Outcomes [O]). Two outcomes were defined: quality of life and the no. of patients with, at least, one adverse event. The search was conducted in the Cochrane Library, MEDLINE, and EMBASE databases; study selection was performed based on pre-defined criteria. The risk of bias was determined in each study.

RESULTS

We obtained a total of 11,363 references, 31 of which met the inclusion criteria. These studies included 1143 patients with HS, 62% of whom were women. A total of 10, 8, 6, 2, and 5 studies, respectively, evaluated the use of photodynamic therapy (PDT), glucocorticoids, resorcinol, topical antibiotics, and other interventions. Most articles were case series (n=25), with only five randomized clinical trials (RCTs) and one cohort study. RCTs showed improvement in disease activity with topical clindamycin and botulinum toxin (BTX) vs placebo, and PDT with methylene blue (MB) niosomal vs free MB; however, intralesional triamcinolone acetonide was not superior to placebo. The risk of bias was low in three RCTs and high in two RCTs.

CONCLUSION

The quality of evidence supporting the use of topical, or IL treatments is low. However, it supports the use of topical clindamycin, PDT, and BTX. Well-designed RCTs with standardized outcomes and homogeneous populations of patients and lesions are needed to support decision-making in the routine clinical practice.

A Retrospective Review of Laser Therapy for Treatment of Hidradenitis Suppurativa

PURPOSE

Hidradenitis suppurativa (HS) is a chronic inflammatory disease characterized by painful and foul-smelling cystic nodules and sinus tracts in the apocrine gland-bearing regions. The treatment options include topical, intralesional, systemic, and surgical modalities. Currently, the most novel therapy is laser therapy to provide localized treatment without systemic adverse effects. However, data regarding patient outcomes after laser treatment are limited because of the low prevalence of this disease. This study aimed to evaluate the efficacy of laser therapy as a treatment modality for patients with HS.

METHODS

A retrospective review cohort analysis of patients with HS undergoing laser treatment between 2016 and 2021 was conducted. Patient demographics, lesion location(s), Hurley stage, age of onset and diagnosis, treatment length, type, outcomes, and complications were analyzed.

RESULTS

Ninety-four patients met the inclusion criteria; on average, patients were treated with 5.8 laser sessions for 14.8 months with no complications and minor blood loss. Hidradenitis suppurativa progression commonly starts during puberty, with a median onset of 13.8 years and diagnosis of HS at 16.2 years. All patients (n = 94) showed an improvement in HS disease severity: 59.6% completed treatment, 12.0% are currently undergoing treatment, and 26.0% were lost to follow-up.

CONCLUSIONS

Laser therapy is an effective and safe therapy for HS leading to improved quality of life and should be considered in the treatment and management of HS.

Systematic review of photodynamic therapy for the treatment of hidradenitis suppurativa

OBJECTIVE

To perform a systematic review of available literature regarding the use of 5-aminolevulinic acid (ALA) and ALA derivative photodynamic therapy (PDT) in the treatment of hidradenitis suppurativa (HS) and provide recommendations on its use.

METHODS

A systematic review was performed of all published studies up to September 1, 2019 from nine databases, including PubMed, that evaluated PDT in the treatment of HS. For each study, quality of evidence and risk of bias was evaluated. Recommendations from the body of evidence were created based on Strength of Recommendation and Taxonomy (SORT) criteria.

RESULTS

Eighteen studies met inclusion criteria. The majority of studies had a high risk of bias. Blue light PDT with 20% ALA and red light PDT with 16% methyl aminolevulinate (MAL) demonstrated some benefit based on a small number of poor-quality studies with a high risk of bias (Grade C, level III evidence). The most promising results were for 1%-5% ALA with intralesional diode, with good to complete response in 78%-94% of anatomic sites treated (Grade B, level II evidence).

LIMITATIONS

The majority of studies contained high levels of bias, with significant heterogeneity between studies. Conclusions are limited by small samples sizes, lack of randomized controlled trials, and differing protocols.

CONCLUSION

Further studies are needed to determine the clinical efficacy of 20% ALA with blue light and MAL with red light. Intralesional diode PDT shows the most promise and warrants further investigation in larger, randomized controlled trials.

Gold-Polypyrrole-Loaded Eosin in Photo-Mediated Treatment of Hidradenitis Suppurativa: In Vivo Trans-Epidermal Permeation Study and Clinical Case Report

This study reports a new protocol for the management of Hidradenitis Suppurativa (HS), depending on the synergistic photodynamic and photothermal effect of eosin yellow-gold-polypyrrole hybrid nanoparticles (E-G-Ppy NPs). E-G-Ppy NPs and gold-polypyrrole NPs (G-Ppy NPs) were synthesized, characterized, and formulated in topical hydrogels. Then, in vivo trans-epidermal permeation study, under both dark and white light-irradiation conditions, was done on albino mice. The E-G-Ppy hydrogel was then applied on a twenty-four years old female with recurrent axillary HS lesions pretreated with fractional CO₂ laser. Thereafter, the treated lesions were irradiated sequentially, using an IPL system, in the visible (~550 nm) and NIR band (630-1100 nm) to activate the synthesized nanoparticles. Results showed that, upon application to mice skin, E-G-Ppy exhibited good tolerance and safety under dark conditions and induced degenerative changes into dermal layers after white-light activation, reflecting deep penetration. Photo-activation of E-G-Ppy hydrogel to a severe Hidradenitis Suppurativa case showed an improvement of 80% of the lesions according to average HS-LASI scores after 4 sessions with no recurrence during a follow-up period of six months. In summary, the dual photodynamic/photothermal activation of E-G-Ppy NPs can represent a promising modality for management of HS. Further expanded clinical studies may be needed.

An insight into photodynamic therapy towards treating major dermatological conditions

Photodynamic therapy (PDT), as the name suggests is a light-based, non-invasive therapeutic treatment method that has garnered immense interest in the recent past for its efficacy in treating several pathological conditions. PDT has prominent use in the treatment of several dermatological conditions, which consequently have cosmetic benefits associated with it as PDT improves the overall appearance of the affected area. PDT is commonly used for repairing sun-damaged skin, providing skin rejuvenation, curbing pre-cancerous cells, treating conditions like acne, keratosis, skin-microbial infections, and cutaneous warts, etc. PDT mediates its action by generating oxygen species that are involved in bringing about immunomodulation, suppression of microbial load, wound-healing, lightening of scarring, etc. Although there are several challenges associated with PDT, the prominent ones being pain, erythema, insufficient delivery of the photosensitizing agent, and poor clinical outcomes, still PDT stands to be a promising approach with continuous efforts towards maximizing clinical efficacy while being cautious of the side effects and working towards lessening them. This article discusses the major skin-related conditions which can be treated or managed by employing PDT as a better or comparable alternative to conventional treatment approaches such that it also brings about aesthetic improvements thereof.

Practical Guidelines for Managing Patients With Hidradenitis Suppurativa: An Update

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disease that is characterized by the formation of comedones, papules, nodules, abscesses and sinus tracts in the axillary, inframammary, groin, and gluteal areas. Up to 3.8% of the Canadian population has HS, though due to a lack of awareness of HS, many patients are initially misdiagnosed and do not receive adequate treatment early on in the disease course. Once a diagnosis of HS is made, developing an effective management plan can be a dilemma for many providers. There is significant variability in response to any given therapy within the HS patient population and many HS patients have other medical comorbidities which must be taken into consideration. The aim of this review is to provide a practical approach for all healthcare providers to diagnose and manage HS and its associated comorbidities. A sample electronic medical record template for HS management was developed by the Canadian Hidradenitis Suppurativa Foundation Executive Board and is intended for use in clinical settings. This will help to increase collaboration between primary healthcare providers, dermatologists, and other medical specialists and ultimately improve the quality of care that HS patients receive.

Intralesional Agents in Dermatology: Pros and Cons

Since introduced in 1961, intralesional (IL) agent has become an essential part of the dermatological practice. The term IL referred to the direct delivery of agent percutaneously into skin lesions. This therapeutic approach is relatively safe, easy to perform and applicable for a broad range of dermatological conditions. On the other hand, immediate side effects, including pain during administration, bleeding, high risk of infection and allergic reaction, and subsequent side effects involving skin changes such as atrophy, telangiectasia, pigmentary changes, and striae are usually associated with this modality. This review paper highlights the pros and cons of IL agents in modern dermatology practice.

Ultrasound-guided photodynamic therapy with intralesional methylene blue and a 635 nm light-emitting diode lamp in hidradenitis suppurativa: A retrospective study of 41 patients

BACKGROUND

Photodynamic therapy for hidradenitis suppurativa (HS) is a therapeutic alternative with a good safety profile, but its effectiveness has yet to be demonstrated.

OBJECTIVES

To demonstrate the effectiveness of PDT with intralesional methylene blue in HS lesions.

METHODS

A retrospective cross-sectional study was performed. Forty-one patients were treated with intralesional methylene blue and a diode lamp. Follow-up was carried out at 1 and 6 months after therapy. Efficacy was determined by the diameter reduction of the lesion measured by high-frequency ultrasound.

RESULTS

A reduction of ≥75% in the maximum diameter was recorded in 58.5% of the lesions, while 22% showed a reduction between 50% and 75%, and 19.5% showed a reduction of <50%. Recurrence rate was 12.5%. The lesions treated in patients with typical forms of HS (Canoui-Poitrine phenotype I) had a better therapeutic response. No statistically significant differences were found in terms of lesion location or concomitant treatment.

CONCLUSION

This therapy may potentially be a cost-effective and well-tolerated local therapy for Hurley I-II patients with superficial abscesses and fistulas.

Intralesional photodynamic therapy in hidradenitis suppurativa: Getting closer to the target

BACKGROUND

The successful treatment of hidradenitis suppurativa (HS) with intralesional photodynamic therapy (IL-PDT) has been previously reported in some case series published a few years ago. We present additional data and patient outcome for this form of PDT.

METHODS

This is an observational retrospective study including all patients diagnosed with HS and treated with IL-PDT in the Hospital Universitari Son Espases from February 2019 to February 2020. Under local or general anesthesia, 5-aminolevulinic acid (5ALA) in gel 2 % or solution 1 % was introduced in the lesion. After two hours, the lesion was intralesionally irradiated (1.4 W, fluence 168 J/cm2) with the tip of a 0.4-mm thick optical fiber connected to a continuous 630-nm diode laser. The main outcome variable was the result (remission, improvement or no change) for each lesion 3 months after the therapy. The result at 6 months and the side effects were secondary outcomes. A multivariate analysis was carried out in order to obtain adjusted odds ratios for no change vs improvement or remission at 3 months for significant variables.

RESULTS

A total of 117 lesions (28 nodules and 89 fistulae) were treated in 42 patients. At 3 months, 26 lesions (22.2 %) had resolved, 73 (62.4 %) had improved in size or symptoms, and 18 (15.4 %) experienced no change. The most frequent side effects were skin burns (53 lesions, 45.3 %), and abscess formation (8 lesions, 6.8 %). In the multivariate analysis, significant variables for no benefit were: a higher International Hidradenitis Suppurativa (IHS4) score, active smoking and gluteal and inguinal location.

CONCLUSIONS

Although our results did not present the level of remission of the previous studies, IL-PDT was useful in most of our patients. Early interventions in patients with lower inflammatory burden were the most valuable.

A Critical Reappraisal of Off-Label Use of Photodynamic Therapy for the Treatment of Non-Neoplastic Skin Conditions

BACKGROUND

In the past 30 years, topical photodynamic therapy (PDT) has been investigated for the treatment of a broad spectrum of cosmetic, inflammatory, and infectious skin conditions with variable, and often contrasting, results. However, the non-expert clinician may be in difficulty evaluating these results because different sensitizers, concentrations, formulations, light sources, and irradiation protocols have been used. In addition, many of these studies have poor quality design being case reports and uncontrolled studies of few cases.

SUMMARY

With the aim to clarify the potential usefulness of PDT for the treatment of infectious and inflammatory skin diseases as well as selected cosmetic indications, we searched for randomized controlled clinical trials, non-randomized comparative studies, retrospective studies, and case series studies with a number of at least 10 patients, published since 1990. Later, we reappraised the results in order to give a simple critical overview. Key Messages: Evidence from the literature seems to strongly support the use of ALA- and MAL-PDT for the treatment of common skin diseases such as acne, warts, condylomata, and Leishmania skin infection and for photorejuvenation, i.e., the correction of selected cosmetic changes of aging and photoaging. For other disorders, the level of evidence and strength of recommendation are lower, and controlled randomized studies with prolonged follow-ups are necessary in order to assess the clinical usefulness and other potential advantages over current treatment options.

Medical and Surgical Management of Hidradenitis Suppurativa: A Review of International Treatment Guidelines and Implementation in General Dermatology Practice

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic painful skin disease that severely impairs patients' quality of life. While high-quality trials of HS therapies remain limited, medical knowledge of best treatment practices is rapidly evolving, leading to the recent publication of multiple international treatment guidelines for HS.

SUMMARY

This review compares international HS treatment guidelines, describes evidence for effectiveness of common and emerging HS therapies, and provides guidance for integrating evidence-based HS care into practice. Although over 50 medical and procedural treatments are mentioned across international HS guidelines, only adalimumab and infliximab have grade B/weak recommendation or higher across all major guidelines. This review describes the appropriate patient selection and effectiveness of the most commonly used medical and procedural treatments for HS. It also includes recommendations for counseling, dosing, and duration of medical therapies as well as procedure videos for the practicing dermatologist.

Laser and Light-Based Treatment Modalities for the Management of Hidradenitis Suppurativa

Hidradenitis suppurativa is a chronic inflammatory skin disease characterized by inflammatory nodules, abscesses, and sinus tracts in intertriginous areas that has a significant impact on patient quality of life. Treatments range from topical, intralesional, systemic, and surgical. Furthermore, laser and light-based treatment options have become increasingly popular because of the limitations of adverse effects associated with systemic therapy and decreased down-time associated with laser and light therapy. These modalities are thought to work through a variety of mechanisms including decreasing inflammation, destroying hair follicles, targeting sebaceous glands, killing bacteria, and debulking lesions through ablation. This review explores these laser and light-based treatment modalities for the treatment of hidradenitis suppurativa.

Photodynamic Therapy for the Treatment of Complex Anal Fistula

BACKGROUND AND OBJECTIVES

To validate and analyze the results of intralesional photodynamic therapy in the treatment of complex anal fistula.

STUDY DESIGN/MATERIALS AND METHODS

This prospective multicentric observational study enrolled patients treated for complex anal fistula who underwent intralesional photodynamic therapy (i-PDT). The included patients were treated from January 2016 to December 2018 with a minimum follow-up of 1 year to evaluate recurrence, continence and postoperative morbidity. Intralesional 5-aminolevulinic acid (ALA) gel (2%) was injected directly into the fistula. The internal and external orifices were closed. After an incubation period of 2 hours, the fistula was irradiated using an optical fiber connected to a red laser (Multidiode 630 PDT) operating at 1 W/cm for 3 minutes (180 J).

RESULTS

In total, 49 patients were included (61.2% male). The mean age was 48 years, and the mean duration of fistula was 13 months. Of the fistulas included, 75.5% were medium transphincteric, and 24.5% were high transphincteric. The median fistula length was 4 ± 1,14 cm (range: 3-5). A total of 41 patients (83.7%) had a previous history of fistula surgery. Preoperatively, some degree of anal incontinence was found in 5 patients (10.2%). No center reported any other procedure-related complications intraoperatively. Phototoxicity was found in one patient. In the first 48 hours after the procedure, fever was reported in 2 patients (4%). At the end of follow-up, total healing was observed in 32/49 patients (65.3%). No patient reported new incontinence postoperatively.

CONCLUSION

i-PDT could be considered a good choice in patients with complex anal fistulas to avoid surgery and its complications. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Quality of life measurement in hidradenitis suppurativa: position statement of the European Academy of Dermatology and Venereology task forces on Quality of Life and Patient-Oriented Outcomes and Acne, Rosacea and Hidradenitis Suppurativa

This paper is organized jointly by the European Academy of Dermatology and Venereology (EADV) Task Force (TF) on Quality of Life (QoL) and Patient-Oriented Outcomes and the EADV TF on acne, rosacea and hidradenitis suppurativa (ARHS). The purpose of this paper was to present current knowledge about QoL assessment in HS, including data on HS-specific health-related (HR) QoL instruments and HRQoL changes in clinical trials, and to make practical recommendations concerning the assessment of QoL in people with HS. HS results in significant quimp that is higher than in most other chronic skin diseases. HS impact in published studies was assessed predominantly (84% of studies) by the Dermatology Life Quality Index (DLQI). There is a lack of high-quality clinical trials in HS patients where HRQoL instruments have been used as outcome measures. One double-blind randomized placebo-controlled trial on infliximab with low number of participants reported significantly better HRQoL improvement in the treatment group than in the placebo group. Well-designed clinical studies in HS patients to compare different treatment methods, including surgical methods and assessing long-term effects, are needed. Because of lack of sufficient validation, the Task Forces are not at present able to recommend existing HS-specific HRQoL instruments for use in clinical studies. The EADV TFs recommend the dermatology-specific DLQI questionnaire for use in HS patients. The EADV TFs encourage the further development, validation and use of other HS-specific, dermatology-specific and generic instruments but such use should be based on the principles presented in the previous publications of the EADV TF on QoL and Patient-Oriented Outcomes.

A narrative review of the definition of 'flare' in hidradenitis suppurativa

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic, inflammatory condition that can have periodic worsening or flares. Measurement of flare is important because it can inform treatment efficacy; however, it is unclear how HS flare should be defined.

OBJECTIVES

This study reviewed the literature for definitions of HS flare.

METHODS

The PubMed MEDLINE online database was searched on 10 January 2018 and the search was repeated on 8 December 2018 for new publications. Titles and abstracts were screened for inclusion. Subsequently, full articles were screened for inclusion. Papers were included if the publication was a systematic review, clinical trial, cohort study, case report or series, or cross-sectional study. Studies were excluded if they were journalistic reviews, did not discuss clinical findings of HS or did not use the words 'flare', 'exacerbation', 'relapse' or 'recurrence'.

RESULTS

Two hundred and seventy-four papers were identified and 154 fulfilled the study criteria. Of these, 27 (17.5%) included the term 'flare' and 16 (10.4%) included the term 'exacerbation'. Two of the 27 papers (7%) defined the term flare and both included patient report of changes in symptoms or signs. One of 16 papers (6%) defined exacerbation, which was taken as one new HS lesion. The terms 'recurrence' and 'relapse' were more apt to be defined: 13% (13 of 100) and 14% (six of 44), respectively.

CONCLUSIONS

The lack of a specific and measurable definition of HS flare is a barrier to assessment of this important outcome. Once a specific and measurable definition is established, validated and reliable measures of HS flare can be incorporated into future studies. What's already known about this topic? Hidradenitis suppurativa (HS) is a chronic, relapsing inflammatory skin condition. The ability to assess flares is important to people who have HS; however, it is unclear how this is defined. HS flare is one of the core outcomes in the core outcome set for HS clinical trials; however, it is unclear how this should be assessed. What does this study add? This literature review reveals the paucity of measurable definitions associated with the use of the term 'flare' in the HS literature. It also highlights the variation and lack of a validated and reliable measure of HS flare.

Treating hidradenitis suppurativa with photodynamic therapy

Hidradenitis suppurativa is a chronic, recurring, and disabling inflammatory condition of the skin. There is no cure for hidradenitis suppurativa and treatment must be adapted to each individual patient. Several studies have been published since 2004 on the use of photodynamic therapy to treat hidradenitis suppurativa. The use of superficial or interstitial illumination with 5-amino-levulinic acid (5-ALA) or methylene blue (MB) have been proposed. Injecting 5-ALA or MB followed by illumination with a fiber optic sensor placed inside the lesion appears to be a better method of treating these thick lesions.

Current and future treatment of hidradenitis suppurativa

This scholarly review on the current and future treatment of hidradenitis suppurativa (HS) focuses on medical and surgical treatment options, while novel pipeline drugs are also discussed. Treatment goals are to limit the incidence and duration of flares, reducing inflammation and suppuration, achieving local cure after surgery and, most importantly, to improve the quality of life of patients with HS. The type of medication and/or surgery should be chosen based on the stage of the disease and the degree of inflammation. However, the lack of a simple scoring system and the lack of clear surgical outcome definitions hamper the interpretation of treatment efficacy and the comparison between different treatment strategies. The therapeutic pipeline for HS is gradually expanding, and will probably lead to a broader panel of more effective therapeutic options.

An update on the pathogenesis of hidradenitis suppurativa: implications for therapy

INTRODUCTION

Hidradenitis suppurativa is a chronic, inflammatory disease characterized by painful nodules, abscesses, and sinuses in the intertriginous areas, with significant associated comorbidities. The pathogenesis remains unclear, although advances have been made in understanding the disease process. Management of the disease is challenging, with a wide range of treatment options available with variable clinical response. Areas covered: This review discusses the most updated studies on the complex pathogenic mechanisms of hidradenitis suppurativa and the relevant literature on the current treatment options for this condition. Expert commentary: There is increasing evidence supporting the role of Th17 cells and enhanced expression of IL-17 and IL-1β, which represent potential targets for therapy. Bacteria and biofilms are likely contributory but secondary drivers of inflammation. There is also evolving evidence to suggest the presence of systemic comorbidities associated with HS, which underlie the importance of better understanding the pathogenesis and treatment of this disease.