Actualización en hidradenitis supurativa (I): epidemiología, aspectos clínicos y definición de severidad de la enfermedad

Treatment Strategies in Neutrophilic Dermatoses: A Comprehensive Review

Neutrophilic dermatoses (NDs) are a group of noninfectious disorders characterized by the presence of a sterile neutrophilic infiltrate without vasculitis histopathology. Their physiopathology is not fully understood. The association between neutrophilic dermatoses and autoinflammatory diseases has led some authors to propose that both are part of the same spectrum of diseases. The classification of NDs depends on clinical and histopathological features. This review focuses on the recent developments of treatments in these pathologies.

Azathioprine in hidradenitis suppurativa with inflammatory phenotype: a case series of 11 patients

BACKGROUND

Hidradenitis suppurativa (HS) is a chronic inflammatory disease that negatively impacts the quality of life of patients. It presents as deep-seated nodules, abscesses, fistulae, sinus tracts, and scars in the axilla, inguinal area, submammary folds, and perianal area. Recently, two phenotypes have been described: a follicular phenotype and an inflammatory phenotype. Numerous medical treatments are available for hidradenitis suppurativa, with particular importance of antitumor necrosis factor antibodies. Due to the association of HS with other conditions with a pro-inflammatory state, particularly Crohn's disease, it has been suggested that azathioprine may have a role in the treatment of HS.

OBJECTIVE

To assess the effectiveness of azathioprine monotherapy in patients with moderate-severe HS.

METHODS

We retrospectively studied patients with HS treated with azathioprine in monotherapy. We performed both clinical and ultrasound evaluation at baseline as well as in the follow-up visits. Their baseline score on the iHS4 and DLQI scales and 12-16 weeks after starting the treatment were compared. We also registered the number of patients who achieved HiSCR.

RESULTS

Six patients presented significant improvement, reducing their score in iHS4 and DLQI scales and achieving HiSCR. Another patient had clinical improvement, meaning reduction in iHS4 and DLQI, but without achieving HiSCR. Two patients stopped the treatment before week 12 because of adverse events. The remaining two patients presented no improvement. The median (Q3-Q1) baseline iHS4 score was 6 (12-6), and follow-up iHS4 score, 4 (6-2), being these differences statistically significant (P = 0.006). Median (Q3-Q1) baseline DLQI scores and 12-16 weeks after treatment were 17 (23-11) and 14 (18-9) although statistically nonsignificant (P = 0.099).

CONCLUSION

We present a case series of 11 patients treated with azathioprine with good clinical and ultrasonographic response. We suggest that azathioprine may benefit a certain patient profile with the inflammatory phenotype.

Paradoxical hidradenitis suppurativa due to anti-interleukin-1 agents for mevalonate kinase deficiency successfully treated with the addition of ustekinumab

Hidradenitis suppurativa (HS) as a paradoxical adverse event (PAE) from using anti-interleukin (IL)-1 has not been reported in the literature, to our knowledge. We herein report a case of paradoxical HS as a result of use of anti-IL-1 agents for mevalonate kinase deficiency disease that was successfully treated with the addition of ustekinumab.

Formulation, long-term physicochemical and microbiological stability of 15% topical resorcinol for hidradenitis suppurativa

OBJECTIVES

Topical resorcinol 15% is a self-treatment for painful hidradenitis suppurativa nodules and abscesses with good results in reducing pain and lesion duration. The aim of this study is to establish a 15% topical resorcinol formula, to develop a physicochemical and microbiological stability study and to further determine the compounding shelf-life in different package conditions following the European Pharmacopoeia (Ph. Eur.) specifications.

METHODS

Physicochemical and microbiological stability studies of the formulation were conducted for 12 months at room temperature (25°C±2°C) in different package conditions: aluminium tubes (aluminium A7-99.7% varnish DF-6172), plastic tubes (low density polyethylene) and amber plastic containers (polyethylene terephthalate). High performance liquid chromatography (HPLC) was developed as a method of indicating the stability of the resorcinol formulation. A microbiological growth assay was also validated according to the Ph. Eur. Physical properties were inspected to determine parameters such as odour, colour, pH, emulsion phase and extensibility index and its evolution.

RESULTS

The HPLC method was validated according to the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH) guidelines. At day 365, visual inspection remained unchanged only for preparations packaged in aluminium tubes. The pH did not vary by more than 0.3 units in all conditions. The extensibility index decreased in the preparations packaged in plastic and amber plastic containers. HPLC analysis conducted over 1 year did not show a degradation greater than 7% of resorcinol in the preparation in plastic and aluminium packages. The ability of ATCC strains to grow in resorcinol formulation was confirmed under the suitability test. Resorcinol packed in aluminium tubes achieved microbiological stability at day 365.

CONCLUSIONS

Only the formulation package in aluminium tubes showed physicochemical and microbiological stability of resorcinol for 12 months at room temperature (25°C±2°C).

New and Emerging Targeted Therapies for Hidradenitis Suppurativa

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease deriving from the hair follicles. The formation of inflammatory nodules, abscesses, fistulas, and sinus tracts is characterized by a large inflow of key pro-inflammatory mediators, such as IFN-γ, TNF-α, IL-1, IL-17, and IL-12/23. Adalimumab is currently the only Food and Drug Administration (FDA)- and European Medicines Agency (EMA)-approved biologic therapy for moderate to severe HS in adults and adolescents. However, the long-term effectiveness of this TNF-α inhibitor in HS patients has shown to be highly variable. This review aims to review the evidence for emerging therapies that target the main pro-inflammatory cytokines in HS pathogenesis. A review of the literature was conducted, using the PubMed and Google Scholar repositories, as well as Clinicaltrials.gov. Presently, the most promising biologics in phase III trials are anti-IL-17 antibodies, secukinumab, and bimekizumab. Furthermore, an anti-IL-1 biologic, bermekimab, is currently in phase II trials, and shows encouraging results. Overall, the clinical efficacies of all new targeted therapies published up to this point are limited. More studies need to be performed to clarify the precise molecular pathology, and assess the efficacy of biological therapies for HS.

Efficacy and Safety of Bimekizumab in Moderate to Severe Hidradenitis Suppurativa: A Phase 2, Double-blind, Placebo-Controlled Randomized Clinical Trial

Question

What is the efficacy and safety of bimekizumab in individuals with moderate to severe hidradenitis suppurativa (HS)?

Findings

In this double-blind, placebo-controlled, phase 2 randomized clinical trial including 90 randomized patients with HS (73 completed the trial), bimekizumab demonstrated clinically meaningful and consistent improvements in participants with HS vs placebo across all assessed outcome measures. Serious adverse events occurred in 2 of 46 bimekizumab-treated participants (4%) and 2 of 21 placebo-treated participants (10%).

Meaning

These initial clinical efficacy and safety data suggest that dual inhibition of interleukin 17A and 17F by bimekizumab may be a viable treatment approach for HS, with the potential to achieve deep responses in clinical outcome measures, and support further evaluation.

Importance

Hidradenitis suppurativa (HS) is a chronic inflammatory disease with a high burden for patients and limited existing therapeutic options.

Objective

To evaluate the efficacy and safety of bimekizumab, a monoclonal IgG1 antibody that selectively inhibits interleukin 17A and 17F in individuals with moderate to severe HS.

Design, Setting, and Participants

This phase 2, double-blind, placebo-controlled randomized clinical trial with an active reference arm was performed from September 22, 2017, to February 21, 2019. The study included a 2- to 4-week screening period, a 12-week treatment period, and a 20-week safety follow-up. Of 167 participants screened at multiple centers, 90 were enrolled. Eligible participants were 18 to 70 years of age with a diagnosis of moderate to severe HS 12 months or more before baseline.

Interventions

Participants with HS were randomized 2:1:1 to receive bimekizumab (640 mg at week 0, 320 mg every 2 weeks), placebo, or reference arm adalimumab (160 mg at week 0, 80 mg at week 2, and 40 mg every week for weeks 4-10).

Main Outcomes and Measures

The prespecified primary efficacy variable was the proportion of participants with a 50% or greater reduction from baseline in the total abscess and inflammatory nodule count with no increase in abscess or draining fistula count (Hidradenitis Suppurativa Clinical Response [HiSCR] at week 12. Exploratory variables included proportion achieving a modified HiSCR with 75% reduction of HiSCR criteria (HiSCR₇₅) or a modified HiSCR with 90% reduction of HiSCR criteria (HiSCR₉₀), change in Patient’s Global Assessment of Pain, and Dermatology Life Quality Index total scores.

Results

Eighty-eight participants received at least 1 dose of study medication (61 [69%] female; median age, 36 years; range, 18-69 years). Seventy-three participants completed the study, including safety follow-up. Bimekizumab demonstrated a higher HiSCR rate vs placebo at week 12 (57.3% vs 26.1%; posterior probability of superiority equaled 0.998, calculated using bayesian analysis). Bimekizumab demonstrated greater clinical improvements compared with placebo. Improvements in the International Hidradenitis Suppurativa Severity Score (IHS4) were seen at week 12 with bimekizumab (mean [SD] IHS4, 16.0 [18.0]) compared with placebo (mean [SD] IHS4, 40.2 [32.6]). More bimekizumab-treated participants achieved positive results on stringent outcome measures compared with placebo. At week 12, 46% of bimekizumab-treated participants achieved HiSCR₇₅ and 32% achieved HiSCR₉₀, whereas 10% of placebo-treated participants achieved HiSCR₇₅ and none achieved HiSCR₉₀; in adalimumab-treated participants, 35% achieved HiSCR₇₅ and 15% achieved HiSCR₉₀. One participant withdrew because of adverse events. Serious adverse events occurred in 2 of 46 bimekizumab-treated participants (4%), 2 of 21 placebo-treated participants (10%), and 1 of 21 adalimumab-treated participants (5%).

Conclusions and Relevance

In this phase 2 randomized clinical trial, bimekizumab demonstrated clinically meaningful improvements across all outcome measures, including stringent outcomes. Bimekizumab’s safety profile was consistent with studies of other indications, supporting further evaluation in participants with HS.

Trial Registration

ClinicalTrials.gov Identifier: NCT03248531

IL-17 in inflammatory skin diseases psoriasis and hidradenitis suppurativa

The skin is one of the most important organs in the body, providing integrity and acting as a barrier to exclude microbes, allergens and chemicals. However, chronic skin inflammation can result when barrier function is defective and immune responses are dysregulated or misdirected against harmless or self-antigens. During the last 15 years interleukin (IL)-17 cytokines have emerged as key players in multiple inflammatory disorders, and they appear to be especially prominent in skin inflammation. IL-17 cytokines produced by T cells and other cell types potently activate keratinocytes to promote inflammation in a feed-forward loop. Given this key pathogenic role of the IL-17 pathway in autoimmune and inflammatory disease, it has been the focus of intense efforts to target therapeutically. The inflammatory effects of IL-17 can be targeted directly by blocking the cytokine or its receptor, or indirectly by blocking cytokines upstream of IL-17-producing cells. Psoriasis has been the major success story for anti-IL-17 drugs, where they have proven more effective than in other indications. Hidradenitis suppurativa (HS) is another inflammatory skin disease which, despite carrying a higher burden than psoriasis, is poorly recognized and under-diagnosed, and current treatment options are inadequate. Recently, a key role for the IL-17 pathway in the pathogenesis of HS has emerged, prompting clinical trials with a variety of IL-17 inhibitors. In this review, we discuss the roles of IL-17A, IL-17F and IL-17C in psoriasis and HS and the strategies taken to target the IL-17 pathway therapeutically.

Development and Preliminary Validation of the HSQoL-24 Tool to Assess Quality of Life in Patients With Hidradenitis Suppurativa

INTRODUCTION AND OBJECTIVES

Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the skin with a negative impact on quality of life. Up to now, there are no disease specific instruments in Spanish to assess quality of life in HS. The objective of this study was to develop and validate a questionnaire to evaluate the quality of life in patients with HS.

MATERIAL AND METHODS

A multicentre study was carried out in Spain between 2016 and 2017 to develop the questionnaire. Both the conceptual framework and understanding of the patient's situation were considered through a review of the literature, consensus of professionals from different related health areas, and in-depth interviews with patients. The resulting questionnaire was passed to a group of 30 patients with 30±10 days of interval between both assessments.

RESULTS

The reliability analysis shows a good internal consistency and reproducibility with Cronbach's alpha score of 0.920 (test) and 0.917 (retest) and intraclass correlation coefficient with DLQI and Skindex-29 of 0.698 IC 95% (0.456-0.844) and 0.900 IC 95% (0.801-0.951) respectively. Cut-off points were established for its use and the instrument was found to be sensitive to change.

CONCLUSIONS

The HSQoL-24 is the first disease-specific self-administered instrument to assess quality of life in patients with HS in Spanish. It is user friendly, and easy to score. This study shows that the instrument is reliable, valid and sensitive to change, pending confirmatory study with a larger sample of 100 patients with HS.

Consensus on the treatment of hidradenitis suppurativa - Brazilian Society of Dermatology

Hidradenitis suppurativa is a chronic immune mediated disease of universal distribution that causes great damage to the quality of life of the affected individual, whose prevalence is estimated at 0.41% in the Brazilian population. The objective of this work was update on physiopathogenesis, diagnosis and classification of hidradenitis suppurativa and to establish therapeutic recommendations in the Brazilian reality. It was organized as a work group composed of eight dermatologists from several institutions of the country with experience in the treatment of hidradenitis suppurativa and carried out review on the topic. Recommendations were elaborated and voted by modified Delphi system and statistical analysis of the results was performed. The Brazilian consensus on the clinical approach of hidradenitis suppurativa had the support of the Brazilian Society of Dermatology.

Hidradenitis Suppurativa: Estimated Prevalence, Clinical Features, Concomitant Conditions, and Diagnostic Delay in a University Teaching Hospital in Buenos Aires, Argentina

BACKGROUND

Hidradenitis suppurativa is a chronic recurrent systemic inflammatory disease that mainly involves large skin folds. It develops when pilosebaceous units become blocked, leading to the formation of painful nodules, abscesses, fistulas, and scarring. The impact of this disease on quality of life is great.

OBJECTIVES

To describe the prevalence and clinical features of hidradenitis suppurativa in patients treated at Hospital Italiano de Buenos Aires and determine the frequency of comorbidities and time to diagnosis in this population.

MATERIAL AND METHODS

Retrospective descriptive cross-sectional study. Information was extracted from the computerized clinical records of all patients with a diagnosis of hidradenitis suppurativa managed in Hospital Italiano de Buenos Aires between July 2012 and October 2017.

RESULTS

Our initial search of the records yielded 180 cases; the diagnosis was confirmed in 66 cases. Sixty-five percent of the patients were women, and the mean age was 37 years. The prevalence of this diagnosis was 0.02%. The armpits, vulva, and groin were the locations most frequently affected. Smoking, overweight, and obesity were the most commonly recorded concomitant conditions. Male sex and perianal and gluteal locations were associated with severity. Time until diagnosis varied widely, ranging from diagnosis at the first visit in some cases to as long as 142 months and 21 visits.

CONCLUSIONS

Our findings are consistent with the literature on hidradenitis suppurativa. This is the first Argentinian study to describe the prevalence of this disease as well as the concomitant conditions found and the rate of diagnostic error.

Association Between Hidradenitis Suppurativa and Metabolic Syndrome: A Systematic Review and Meta-analysis

BACKGROUND

Recent studies have shown a relationship between hidradenitis suppurativa (HS) and metabolic syndrome (MS), but the literature offers no meta-analysis restricted to studies that have been adjusted for confounders.

OBJECTIVE

To determine the association between HS and MS.

METHODS

A systematic review and meta-analysis of observational studies on HS and MS in adults. We searched MEDLINE, SCOPUS, SCIELO, Google Scholar, Science Direct, and LILACS from the inception of the databases to January 2016. We performed a random effects model meta-analysis for studies reporting adjusted and crude odds ratios (ORs) with 95% CIs. A subgroup analysis was related to the type of HS patient (general patients vs hospital patients) and age group (adults vs children and adults).

RESULTS

Five studies including 3950 HS patients were analyzed. We found that MS was pres-ent in 9.64% of HS patients (OR, 1.82; 95%, CI 1.39-2.25). Studies from tertiary care hospital dermatology clinics (OR, 2.82; 95% CI, 0.58-5.06) reported a greater risk for MS than studies carried out in patients treated outside hospitals (OR, 1.78; 95% CI, 1.34-2.22). Studies that included pediatric populations reported a significant association (OR, 2.10; 95% CI, 1.58-2.62).

LIMITATION

Few of the included studies reported adjusted ORs.

CONCLUSIONS

HS patients have an increased risk for MS. Clinicians should consider screening HS patients for metabolic risk factors.

The role of nutrition in inflammatory pilosebaceous disorders: Implication of the skin-gut axis

Nutrition plays a critical role in the manifestation and management of inflammatory pilosebaceous disorders. There is rich potential for insight into the impact of dietary effects on the pathophysiology of inflammatory pilosebaceous disorders including acne vulgaris, hidradenitis suppurativa, rosacea, and the closely related seborrhoeic dermatitis. Acne vulgaris and hidradenitis suppurativa are thought to have similar diet-modulating pathogenic pathways. Western diet influences Acne vulgaris and hidradenitis suppurativa by increasing insulin and modulating FOX01/mTOR, resulting in over-expression of cytokeratins, hyperproliferation of keratinocytes, and hypercornification of the follicular wall. Key receptors in rosacea are alternatively activated by UV radiation, hot beverages, spicy foods, vanilla, cinnamon, caffeine, alcohol, cold temperatures, and niacin- and formalin-containing foods, to increase oedema and flushing, resulting in erythema, telangiectasia, and warmth, characteristic features of the condition. Seborrhoeic dermatitis, while not a follicular disorder, is closely related, and can be modulated by dietary influences, such as biotin and probiotics. This overview summarizes the role that nutrition plays on these disorders, and identifies dietary modifications as potential adjunctive therapies.

Cutaneous Lesions of the External Genitalia

Individuals with cutaneous diseases of the external genitalia often initially present to their primary care provider. When present, these conditions may be associated with considerable physical symptoms and psychological distress. Dermatoses affecting the genitals may be of infectious, inflammatory, or neoplastic cause, and can be processes confined to the genitalia or a manifestation of a more widespread dermatologic condition. This article provides a guide to recognizing and managing common genital dermatoses and when to refer for specialist opinion.

Clinical and histopathological characteristics in patients with scarring folliculitis type of acne inversa

Objective: This study was designed to study the clinical and histopathological characteristics of patients with the scarring folliculitis type acne inversa in Chinese population.

Methods: A total of 21 patients with acne inversa and 6 controls without known dermatological disease were recruited from outpatient department of dermatology and orthopedic surgery. Two-millimeter punch biopsies were taken from 8 patients with acne inversa and 6 controls, fixed in formalin, embedded in paraffin and stained with haematoxylin and eosin prior to histopathological analysis.

Results: There were 12 patients (57.14%) belonging to the scarring folliculitis type presented with double comedones, papules, nodules, depressed scars, and were mainly Hurley stage I (66.67%). Many of the scarring folliculitis type were smokers (58.33%), some had a history of occupational exposure (41.67%) and some were overweight (50%), the mean BMI of which is 25.18±3.16 kg/m². Histopathological changes such as perifollicular inflammation can be observed in scarring folliculitis type of acne inversa and controls as well. However, epidermal hyperplasia, follicular hyperplasia, sebaceous gland disappearance, destruction of hair follicle and sebaceous gland, collagen hyperplasia, perivascular inflammation, granulomatous inflammation, Micro thrombus were only seen in scarring folliculitis type. The mean surface area in patients (8073.36±15798.43 μm²) was smaller than that in controls (302059.08±502813.78 μm²), with statistically significant difference. (P = 0.024).

Conclusion: The scarring folliculitis type in acne inversa in Chinese population could be characterized by depressed scars, double-ended comedones, epidermal cysts and had high proportion of smokers, or occupational exposure with lower Hurley stage, as well as diminished sebaceous gland. Further studies are needed to clarify the relations between the clinical subtypes of acne inversa and their corresponding genetypes.

The Clinical Significance of Increased Serum Proinflammatory Cytokines, C-Reactive Protein, and Erythrocyte Sedimentation Rate in Patients with Hidradenitis Suppurativa

Objectives

To assess inflammatory serum markers including serum proinflammatory cytokines, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) according to the clinical inflammatory activity of patients with hidradenitis suppurativa (HS).

Patients and Methods

Seventy-four patients with HS were studied based on the Hidradenitis Suppurativa-Physician Global Assessment (HS-PGA) score and Hurley staging system. Proinflammatory cytokines were measured using a multiplex cytokine assay. Twenty-two healthy volunteers were recruited.

Results

Serum interleukin- (IL-) 6, IL-23, soluble tumour necrosis factor alpha (TNF-α) receptor I (sTNF-RI), CRP, and ESR were different in the patients with HS compared with those in the healthy controls (P < 0.05). The levels of IL-1β, IL-6, IL-8, IL-10, IL-12p70, IL-17A, sTNF-RII, CRP, and ESR were significantly elevated according to inflammatory activity based on HS-PGA scores (r > 0.25, P < 0.05). The levels of IL-6 (r = 0.53, P < 0.001), CRP (r = 0.54, P < 0.001), and ESR (r = 0.60, P < 0.001) were especially well correlated with clinical inflammatory activity based on HS-PGA scores. The levels of IL-6, IL-8, sTNF-RI, sTNF-RII, CRP, and ESR were significantly elevated according to Hurley staging system.

Conclusions

Serum proinflammatory cytokines, CRP, and ESR are increased in relation to the clinical inflammatory activity of patients with HS compared with healthy controls. Serum IL-6, CRP, and ESR are effective biomarkers for evaluating the severity of HS.

Hidradenitis Suppurativa Is Characterized by Dysregulation of the Th17:Treg Cell Axis, Which Is Corrected by Anti-TNF Therapy

Hidradenitis suppurativa (HS) is a chronic, inflammatory, and debilitating disease of hair follicles with 1-4% prevalence and high morbidity. There is a dearth of information on the pathogenesis and immune dysregulation underlying HS; therefore, we carried out a detailed analysis of skin-infiltrating T cells. Cells isolated from skin biopsy samples and blood from HS patients and healthy control subjects were analyzed by 16-parameter flow cytometry to provide detailed profiles of CD4 T-cell subsets. We observed substantial infiltration of inflammatory T cells with a striking T helper (Th) type 17-skewed cytokine profile in HS skin; these cells expressed the Th17 lineage marker CD161 and IL-17, as well as proinflammatory cytokines GM-CSF, IL-22, IFN-γ, and tumor necrosis factor. Regulatory T cells were also enriched in HS lesional skin; however, the ratio of Th17 to regulatory T cells was nonetheless highly dysregulated in favor of Th17 cells. In contrast, lesional skin from anti-tumor necrosis factor-treated HS patients who showed substantial clinical improvement exhibited a significant reduction in the frequency of Th17 cells and normalization of the Th17 to regulatory T cell ratio. These data suggest that inhibition of pathogenic IL-17 via tumor necrosis factor blockade is associated with improvement in immune dysregulation in HS and may provide a rationale for targeting IL-17 in the disease.

Predicting Severity of Disease-Causing Variants

Most diseases, including those of genetic origin, express a continuum of severity. Clinical interventions for numerous diseases are based on the severity of the phenotype. Predicting severity due to genetic variants could facilitate diagnosis and choice of therapy. Although computational predictions have been used as evidence for classifying the disease relevance of genetic variants, special tools for predicting disease severity in large scale are missing. Here, we manually curated a dataset containing variants leading to severe and less severe phenotypes and studied the abilities of variation impact predictors to distinguish between them. We found that these tools cannot separate the two groups of variants. Then, we developed a novel machine-learning-based method, PON-PS (http://structure.bmc.lu.se/PON-PS), for the classification of amino acid substitutions associated with benign, severe, and less severe phenotypes. We tested the method using an independent test dataset and variants in four additional proteins. For distinguishing severe and nonsevere variants, PON-PS showed an accuracy of 61% in the test dataset, which is higher than for existing tolerance prediction methods. PON-PS is the first generic tool developed for this task. The tool can be used together with other evidence for improving diagnosis and prognosis and for prioritization of preventive interventions, clinical monitoring, and molecular tests.

How to Define Pathogenicity, Health, and Disease?

Scientific and clinical communities produce ever increasing amounts of data and details about health and disease. Our ability to understand and utilize this information is limited because of imprecise language and lack of well-defined concepts. This problem involves also the principal concepts of health, disease, and pathogenicity. Here, a systematic model is presented for pathogenicity, as well as for health and disease. It has three components: extent, modulation, and severity, which jointly define the continuum of pathogenicity. The model is population based, and once implemented, it can be used for numerous purposes such as diagnosis, patient stratification, prognosis, finding phenotype-genotype correlations, or explaining adverse drug reactions. The new model has several benefits including health economy by allowing evidence-based personalized/precision medicine.

Spotlight on adalimumab in the treatment of active moderate-to-severe hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, recurrent, inflammatory skin disease that affects the hair follicles of the aprocrine gland-bearing anatomical areas of the body. It is characterized by deep painful nodules and abscesses that rupture and contribute to the formation of sinus tracks and scarring. The management of HS is based on the assessment of disease severity and a combination of medical and surgical treatment according to the European Guidelines. Adalimumab, a recombinant, fully humanized, anti-tumor necrosis factor alpha (anti-TNF-α) monoclonal antibody, is the only officially approved treatment for the management of moderate-to-severe HS. Case reports, concerning 42 patients who received adalimumab for severe HS (with the standard dose regimen for psoriasis), reported a cumulative response rate of 58% (≥50% in 23 patients) with a relapse rate of 71% (10 out of 14 patients). The most recent and most well-powered phase III, randomized placebo-controlled trials for the evaluation of the efficacy and safety of adalimumab in treatment of moderate-to-severe HS (PIONEER studies I and II) showed that the Hidradenitis Suppurativa Clinical Response (HiSCR) rate at week 12 was significantly higher for patients randomized to adalimumab compared to placebo. Adverse events were comparable to placebo. In conclusion, adalimumab, to date, holds the most robust data regarding treatment efficacy in HS. Larger, registry-based studies are needed to further establish the efficacy and safety profile of this anti-TNF-α agent in HS.