Prevalence and comorbidities associated with hidradenitis suppurativa in Korea: a nationwide population-based study

Response to adalimumab in Caucasian and Asian patients with hidradenitis suppurativa: A retrospective cohort study of an Australian cohort stratified by patient-reported ethnicity

BACKGROUND/OBJECTIVES

Caucasian and Asian patients with hidradenitis suppurativa demonstrate significant differences with regard to age, gender and body mass index. Demographic characteristics are known to influence the efficacy and drug survival of hidradenitis suppurativa therapeutics including biologic therapies. What remains unknown is the impact of ethnicity upon the efficacy of therapeutics once demographic and disease characteristics have been taken into account. This is an important question given the expansion of biologic therapies for HS into the global patient community.

METHODS

We assessed 170 patients from a single HS specialist centre in Australia stratified by patient-identified ethnicity including those identifying as either Caucasian or Asian.

RESULTS

Asian patients demonstrated lower BMI, higher rates of smoking and greater odds of Hurley stage 3 disease with tunnels than Caucasian patients in line with the reported literature. There was no significant difference between percentage of individuals achieving HiSCR50 or IHS4-55 at Week 16. Significant differences were seen in median time to secondary loss of response, and Kaplan-Meier curve analysis showed a significant difference between curves when stratified by patient-reported ethnicity. Cox regression analysis demonstrated after accounting for age, gender, BMI, smoking and Hurley stage, the significance of ethnicity in influencing time to secondary loss of response disappears.

CONCLUSIONS

Caucasian or Asian ethnicity does not influence response to adalimumab treatment on patients with hidradenitis suppurativa.

S2k‐Leitlinie zur Therapie der Hidradenitis suppurativa/Acne inversa – Kurzfassung

Die S2k‐Leitlinie der Hidradenitis suppurativa/Acne inversa (HS/AI) soll eine akzeptierte Entscheidungshilfe für die Auswahl/Durchführung einer geeigneten/suffizienten Therapie liefern. Hidradenitis suppurativa/Acne inversa ist eine chronisch‐rezidivierende, entzündliche, potenziell mutilierende Hauterkrankung des terminalen Haartalgdrüsenapparats, mit schmerzhaften, entzündlichen Läsionen in den apokrinen drüsenreichen Körperregionen. Ihre Punktprävalenz in Deutschland ist 0,3%, sie wird mit einer Verspätung von 10,0 ± 9,6 Jahren diagnostiziert. Abnormale Differenzierung der Keratinozyten des Haartalgdrüsenapparats und eine begleitende Entzündung bilden die zentrale pathogenetische Grundlage. Primäre HS/AI‐Läsionen sind entzündliche Knoten, Abszesse und drainierende Tunnel. Rezidive in den letzten 6 Monaten mit mindestens zwei Läsionen an den Prädilektionsstellen verweisen auf eine HS/AI mit einer 97‐prozentigen Genauigkeit. HS/AI‐Patienten leiden an einer deutlichen Einschränkung der Lebensqualität. Zur korrekten Therapieentscheidung sollen Klassifikation und Aktivitätsbewertung mit einem validierten Instrument erfolgen, wie dem International Hidradenitis Suppurativa Severity Scoring System (IHS4). Hidradenitis suppurativa/Acne inversa wird nach der Ausprägung der nachweisbaren Entzündung in zwei Formen eingeteilt: aktive, entzündliche (milde, mittelschwere und schwere nach IHS4) und vorwiegend inaktive, nicht entzündliche (Hurley‐Grad‐I, ‐II und ‐III) HS/AI. Orale Tetrazykline oder eine 5‐tägige intravenöse Therapie mit Clindamycin sind mit der Effektivität von Clindamycin/Rifampicin vergleichbar. Subkutan applizierbares Adalimumab, Secukinumab und Bimekizumab sind für die Therapie der HS/AI zugelassen. Für die vorwiegend nicht entzündliche Erkrankungsform stehen verschiedene operative Verfahren zur Verfügung. Medikamentöse/chirurgische Kombinationen gelten als ganzheitliches Therapieverfahren.

S2k guideline for the treatment of hidradenitis suppurativa / acne inversa - Short version

The S2k guideline on hidradenitis suppurativa/acne inversa (HS/AI) aims to provide an accepted decision aid for the selection/implementation of appropriate/sufficient therapy. HS/AI is a chronic recurrent, inflammatory, potentially mutilating skin disease of the terminal hair follicle-glandular apparatus, with painful, inflammatory lesions in the apocrine gland-rich regions of the body. Its point prevalence in Germany is 0.3%, it is diagnosed with a delay of 10.0 ± 9.6 years. Abnormal differentiation of the keratinocytes of the hair follicle-gland apparatus and accompanying inflammation form the central pathogenetic basis. Primary HS/AI lesions are inflammatory nodules, abscesses and draining tunnels. Recurrences in the last 6 months with at least 2 lesions at the predilection sites point to HS/AI with a 97% accuracy. HS/AI patients suffer from a significant reduction in quality of life. For correct treatment decisions, classification and activity assessment should be done with a validated tool, such as the International Hidradenitis Suppurativa Severity Scoring System (IHS4). HS/AI is classified into two forms according to the degree of detectable inflammation: active, inflammatory (mild, moderate, and severe according to IHS4) and predominantly inactive, non-inflammatory (Hurley grade I, II and III) HS/AI. Oral tetracyclines or 5-day intravenous therapy with clindamycin are equal to the effectiveness of clindamycin/rifampicin. Subcutaneously administered adalimumab, secukinumab and bimekizumab are approved for the therapy of HS/AI. Various surgical procedures are available for the predominantly non-inflammatory disease form. Drug/surgical combinations are considered a holistic therapy method.

Autoimmune, Autoinflammatory Disease and Cutaneous Malignancy Associations with Hidradenitis Suppurativa: A Cross-Sectional Study

BACKGROUND

Hidradenitis suppurativa (HS) is a debilitating cutaneous disease characterized by severe painful inflammatory nodules/abscesses. At present, data regarding the epidemiology and pathophysiology of this disease are limited.

OBJECTIVE

To define the prevalence and comorbidity associations of HS.

METHODS

This was a cross-sectional study of EPICTM Cosmos© examining over 180 million US patients. Prevalences were calculated by demographic and odds ratios (OR) and identified comorbidity correlations.

RESULTS

All examined metabolism-related, psychological, and autoimmune/autoinflammatory (AI) diseases correlated with HS. The strongest associations were with pyoderma gangrenosum [OR 26.56; confidence interval (CI): 24.98-28.23], Down syndrome (OR 11.31; CI 10.93-11.70), and polycystic ovarian syndrome (OR 11.24; CI 11.09-11.38). Novel AI associations were found between HS and lupus (OR 6.60; CI 6.26-6.94) and multiple sclerosis (MS; OR 2.38; CI 2.29-2.48). Cutaneous malignancies were largely not associated in the unsegmented cohort; however, among Black patients, novel associations with melanoma (OR 2.39; CI 1.86-3.08) and basal cell carcinoma (OR 2.69; CI 2.15-3.36) were identified.

LIMITATIONS

International Classification of Diseases (ICD)-based disease identification relies on coding fidelity and diagnostic accuracy.

CONCLUSION

This is the first study to identify correlations between HS with melanoma and basal cell carcinoma (BCC) among Black patients as well as MS and lupus in all patients with HS.

Pilonidal Sinus Disease is Associated with Severe Hidradenitis Suppurativa in a Spanish Cohort

Hidradenitis suppurativa is a chronic inflammatory disorder of the hair follicle with a high level of morbidity. Pilonidal sinus disease is a comorbid disorder and may be the reason for first contact with the healthcare system of patients with hidradenitis suppurativa. The aim of this study was to evaluate the frequency of association of pilonidal sinus disease and hidradenitis suppurativa and to explore whether pilonidal sinus disease defines a different clinical profile for patients with hidradenitis suppurativa. A cross-sectional study in which data regarding past history of pilonidal sinus disease, clinical and sociodemographic information were recorded during the first visit to the Hidradenitis Suppurativa Clinic of 2 tertiary hospitals. A total of 839 patients were included in the study. Of these, 51.7% (434/839) were male and mean age was 37.3 ± 13.6 years. Pilonidal sinus disease was present in 32.6% (269/839) of the patients and was associated with an early debut of hidradenitis suppurativa, a higher Hurley stage, inflammatory phenotype and a greater number of fistulas and perianal involvement. Elapsed time between pilonidal sinus disease and diagnosis of hidradenitis suppurativa was associated with higher disease severity. Pilonidal sinus disease is a frequent comorbidity and risk marker for hidradenitis suppurativa disease severity. Pilonidal sinus disease could be a sentinel event to identify patients who would benefit from close treatment and follow-up.

Knowledge, attitudes, and perceptions of hidradenitis suppurativa among young adults in Singapore

Background

The prevalence of hidradenitis suppurativa (HS) is 0.00033% to 4.10% globally. Few epidemiological studies derive from Asia, with social stigmatization postulated to result in under-diagnosis.

Objective

This study aimed to assess the self-reported prevalence of HS, and the knowledge, attitudes, and perceptions towards HS among Singaporean young-adults.

Methods

A cross-sectional study (n = 158) was conducted by anonymous online questionnaire. The association between demographic factors and risk of potentially undiagnosed HS was evaluated using multivariable logistic regression. Differences between attitude-perception scores by demographic factors and knowledge of HS were tested using two-sample t-tests.

Results

The prevalence of diagnosed and potentially undiagnosed HS was 0.63% and 8.9%, respectively. Non-Chinese had significantly higher social attitude-perception scores than Chinese (P = .029). Females had significantly higher social (P = .048) as well as economic and work (P = .037) attitude-perception scores than males. Those with knowledge of HS had significantly higher attitude-perception scores for interpersonal (P = .031) and social (P = .0052) subsections.

Limitations

Small sample size, low frequency of HS cases, and self-reported prevalence may not generalize to the broader population in Singapore.

Conclusion

Our results suggest a potential underdiagnosis of HS. Non-Chinese stigmatize HS less than Chinese, and females less than males. Individuals with knowledge of HS might be more open to interpersonal and social interactions with HS sufferers.

Epidemiology of hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, inflammatory, recurrent skin disease affecting hair follicles in predominantly intertriginous areas, characterized by deep, painful nodules and abscesses, fistulas, sinus tracts, and scarring. The estimated global prevalence of HS is highly variable, as revealed in a growing body of published literature, and ranges from 0.053% to 4.1%. In North American and European patients, HS is three times more common in women than men, whereas in South Korea and Japan, male predominance is found. The disease most frequently manifests itself between the ages of 18 and 29. Numerous published studies have reported the association between smoking, obesity, and HS, although there are limitations in confirming the causal relationship due to the retrospective design of the available studies. Case-control studies have frequently evaluated the association between HS, metabolic syndrome, and other systemic comorbidities. Due to increased mental health problems, a higher risk of suicide in patients with HS has been reported. We provide up-to-date evidence about the epidemiology, genetic and environmental risk factors, comorbidities, and quality of life of patients with HS. The divergence in HS frequency, possibly due to differences in populations and methodologies, remains to be explained in future worldwide studies.

Hidradenitis suppurativa and psoriasis: the odd couple

Psoriasis and hidradenitis suppurativa are chronic inflammatory skin diseases that can develop together, negatively impacting on the patient's quality of life. We aimed to review the most up-to-date information regarding the epidemiology, pathogenesis, clinical presentation and possible therapeutical choices in patients with both psoriasis and hidradenitis suppurativa, thus linking these two autoimmune and autoinflammatory conditions. A narrative review of articles dating from 2017 to 2022 has been performed using the PubMed database. We analyzed the case reports and case series found in the literature regarding patients who suffered from both psoriasis and HS. Psoriasis arose before hidradenitis suppurativa in the majority of cases, while only a minority of them had hidradenitis suppurativa before psoriasis. Interestingly, some patients suffered from paradoxical hidradenitis suppurativa following biological therapy administered to treat the already present psoriasis. Lastly, new biological drugs have been marketed with great success for the outcome of psoriasis, but similar progress did not happen for hidradenitis. Novel therapeutic approaches and lines of research are needed for the treatment of these pathologies, even if concomitant, in order to improve patient's quality of life.

Sex-biased immunological processes drive hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that can manifest with abscesses, sinus tracts, and scarring in the intertriginous areas of the body. HS is characterized by immune dysregulation, featuring elevated levels of myeloid cells, T helper (Th) cells, and pro-inflammatory cytokines, particularly those involved in Th1- and Th17-mediated immunity. In most epidemiological studies, HS shows a strong female sex bias, with reported female-to-male ratios estimated at roughly 3:1, suggesting that sex-related factors contribute to HS pathophysiology. In this article, we review the role of intrinsic and extrinsic factors that contribute to immunological differences between the sexes and postulate their role in the female sex bias observed in HS. We discuss the effects of hormones, X chromosome dosage, genetics, the microbiome, and smoking on sex-related differences in immunity to postulate potential immunological mechanisms in HS pathophysiology. Future studies are required to better characterize sex-biased factors that contribute to HS disease presentations.

Epidemiology and comorbidity of hidradenitis suppurativa in Korea for 17 years: A nationwide population-based cohort study

Hidradenitis suppurativa (HS) is associated with various metabolic and autoimmune diseases. The epidemiology has been analyzed in various studies worldwide. However, epidemiological data on HS for Asian populations are limited. This study aimed to analyze the change in the prevalence and incidence of HS over 17 years in South Korea using the Korean National Health Insurance Service (NHIS) database. This study also evaluated the comorbidities in patients with HS. Population-based data from the NHIS database of Korea were obtained between January 2003 and December 2019. Odds ratios were estimated to determine the association between comorbidities and HS during the study period. Hazard ratios for the risk of incident comorbidities in patients with HS were obtained using the multivariable Cox proportional hazard analysis. This study included 45 511 patients with HS and 910 220 controls matched for age, sex, insurance type, and income level. The incidence rate of HS per 1 000 000 person-years in Korea increased from 11.69 in 2003 to 78.78 in 2019. The annual prevalence per 1 000 000 people also increased from 34.68 in 2003 to 140.10 in 2019, showing a similar trend. Many comorbidities, including atopic, metabolic and end-organ, autoimmune/inflammatory, and psychiatric diseases were associated with HS at baseline. In many diseases, the risk of incident comorbidities in patients with HS was higher than that in controls. The incidence and prevalence of HS in Korea have increased over the past 17 years. Various comorbidities, including allergic diseases, hypertension, diabetes mellitus, dyslipidemia, myocardial infarction, chronic hepatitis and cirrhosis, chronic kidney disease, inflammatory bowel diseases, rheumatoid arthritis, vitamin D deficiency, and psychiatric diseases, were associated with HS. Physicians need to keep in mind and closely monitor these comorbidities in patients with HS.

The Development of Systemic Inflammatory Diseases in Hidradenitis Suppurativa

It is understood that the skin is a peripheral lymphoid tissue that defends against external environmental stimuli. Continuous activation from these factors, on the other hand, promotes persistent inflammation at the local location and, occasionally, tissue damage. Hidradenitis suppurativa (HS) is a typical inflammatory skin disease and becomes a source of numerous inflammatory cytokines due to the chronic intractable repeated inflamed tissues. Because inflammatory cells and cytokines circulate throughout the body from the inflamed organ, it has been hypothesized that HS-mediated skin inflammation impacts the systemic functioning of numerous organs. Recent updates to clinical and experimental investigations revealed that HS has a significant connection with systemic inflammatory disorders. We provide the details and comprehensive molecular mechanisms associated with systemic inflammatory illnesses due to HS.

A Practical Guide for Primary Care Providers on Timely Diagnosis and Comprehensive Care Strategies for Hidradenitis Suppurativa

Hidradenitis suppurativa is a chronic, progressive inflammatory disease of the skin with many systemic implications. Hidradenitis suppurativa is frequently underdiagnosed or misdiagnosed, particularly because of heterogeneity in presentation and low disease recognition. Patients can see multiple types of health care providers, including primary care providers, along their journey to an accurate diagnosis. This review provides a comprehensive overview of the clinical presentation, associated comorbidities, and life impact associated with hidradenitis suppurativa. Disease features described here can facilitate earlier identification of hidradenitis suppurativa, differentiation from common mimickers, and timely referrals for multidisciplinary management when needed. Engagement of the medical community will also support comprehensive care strategies necessary in hidradenitis suppurativa.

Incidence, Risk Factors, and Prognosis of Hidradenitis Suppurativa Across the Globe: Insights from the Literature

Hidradenitis suppurativa, a chronic inflammatory disease of the skin, affects a patient's quality of life to a greater extent. While the disease burden, including its incidence and prevalence, has been extensively studied in the western population, there is a paucity of data from developing countries on the epidemiology of Hidradenitis suppurativa. Therefore, a general literature review was conducted to shed light on the epidemiology of Hidradenitis suppurativa across the globe. We reviewed the most recently available information on epidemiology, including incidence, prevalence, risk factors, prognosis and quality of life, complications, and associated comorbid among patients with Hidradenitis suppurativa. The estimated global prevalence of Hidradenitis suppurativa is found to be 0.00033-4.1%, with a relatively higher prevalence of 0.7-1.2% in European and US populations. Both genetic and environmental factors are associated with Hidradenitis suppurativa. Patients with Hidradenitis suppurativa have associated comorbid such as cardiovascular disease, type II diabetes mellitus, mental health issues, and sleep and sexual dysfunctions. These patients spend poor quality of life and tend to be less productive. Future studies are needed to assess the burden of Hidradenitis suppurativa in developing countries. Since the disease tends to be underdiagnosed, future studies should rely on clinical diagnosis rather than self-reporting to avoid the potential of recall bias. Attention needs to be diverted to developing countries with less amount of data on Hidradenitis suppurativa.

The association between pilonidal sinus disease and hidradenitis suppurativa: a systematic review and meta-analysis

We performed a systematic review and meta-analysis examining the association between hidradenitis suppurativa (HS) and pilonidal sinus disease (PSD). We found a strong association between HS and PSD, with an increased occurrence of PSD in individuals with HS compared with unaffected controls. Given this strong association, patients with HS should be assessed for PSD.

All-Cause and Cause-Specific Mortality Risks among Patients with Hidradenitis Suppurativa: A Korean Nationwide Population-Based Cohort Study

Although previous studies have reported increased mortality in patients with hidradenitis suppurativa (HS), the cause-specific mortality and the clinical characteristics attributable to greater mortality remain unclear. The aim of this study was to investigate all-cause and cause-specific mortality risks associated with HS. A retrospective population-based cohort study using the data linkage of the Nationwide Health Insurance Service database and the National Death Registry of Korea was conducted. Patients were defined as individuals with ≥3 documented visits with HS from 2003 to 2019. Controls were matched at a 1:10 ratio with age, sex, insurance type, and income level. The study included 26,304 patients with HS and 263,040 controls. Patients with HS showed a higher risk of all-cause mortality (hazard ratio = 1.152, 95% confidence interval = 1.051-1.263) than controls. However, the difference was comparable after further adjustment for body mass index, smoking, drinking, and comorbidity (adjusted hazard ratio = 1.038, 95% confidence interval = 0.946-1.138). For cause-specific mortality, the mortality from suicide/psychiatric disease (adjusted hazard ratio = 1.449, 95% confidence interval = 1.098-2.911) and renal/urogenital disease (adjusted hazard ratio = 1.801, 95% confidence interval = 1.080-3.004) were independently higher among patients with HS even after adjustment for the confounding factors.

Risk of liver dysfunction and non-alcoholic fatty liver diseases in people with hidradenitis suppurativa: A systematic review and meta-analysis of real-world evidences

Background

To date, evidences with high evidence-level evaluating the association between liver diseases and hidradenitis suppurativa was lacking. Given that inconsistency exists in some of the previous observational studies, evaluating the prevalence of liver diseases in HS patients could potentially serve as a reference of future guidelines for HS comorbidity screening. The aim of the current study was to evaluate potential association between hidradenitis suppurativa and liver diseases and provide integrated evidences.

Methods

A search in PubMed, Web of Science and Embase based on the syntaxes ''hidradenitis suppurativa'' or ''acne inversa'' with "comorbidities", "liver diseases", "fatty liver" or "hepatitis" was performed. Observational studies evaluating epidemiological association between hidradenitis suppurativa and the risk of all liver diseases, including specific diseases as non-alcoholic fatty liver disease, hepatitis B, hepatitis C were targeted to be extracted in this systematic review and meta-analysis.

Results

Within the initial 702 records, there were finally 8 real-world observational studies extracted. Results suggest that patients with HS are associated with all liver diseases (OR= 1.50; 95% CI, 1.27, 1.76), non-alcoholic fatty liver disease (OR= 1.78; 95% CI, 1.28, 2.48) and hepatitis B (OR=1.48; 95% CI, 1.12, 1.94), but not hepatitis C (OR= 1.27; 95% CI, 0.78, 2.07). HS patients were associated with significantly increased risk of liver diseases, especially the risk of non-alcoholic fatty liver disease and hepatitis B.

Conclusions

Clinicians should be alert to the clinical relationship while caring people with hidradenitis suppurativa and the screening of liver function should be recommended to HS patients.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022296034.

The Role of Hormones in Hidradenitis Suppurativa: A Systematic Review

Hidradenitis suppurativa (HS) is a chronic inflammatory disease manifesting in inverse body regions. In a systematic review, the role of hormones in HS will be presented to better understand the pathomechanisms of HS. The review is based on the PRISMA criteria. Systematic research was carried out using keywords. Subsequently, the data were analyzed based on the clinical response and other relevant information. The main focus of our systematic review was on HS manifestation, exacerbation, sex hormones, antiandrogen therapy, thyroid function, polycystic ovary syndrome, insulin resistance, and adipokines. In HS, there appears to be a dysregulated adipokine release that is shifted towards pro-inflammatory adipokines. Insulin resistance is significantly more common in HS than in healthy patients regardless of BMI, age, and gender. Insulin resistance in HS patients leads to further cardiovascular disease. The mechanism of insulin resistance and role of adipokines should be investigated in future studies to better provide the pathomechanisms of HS. The role of androgens seems to be important in a certain subgroup of female patients. Anti-androgenic therapy can be useful and helpful in some patients. However, further studies are needed to better understand the hormonal relationship in HS.

Risk of psoriasis in people with hidradenitis suppurativa: A systematic review and meta-analysis

Background

Hidradenitis suppurativa were associated with comorbidities in various organ systems. Inflammatory dermatological diseases such as pyoderma gangrenosum were reported to be associated with hidradenitis suppurativa. Nevertheless, as for the association between hidradenitis suppurativa and psoriasis, evidences were insufficient. In many studies, the association between psoriasis and hidradenitis suppurativa has been reported. However, some evidence seems to be controversial. The purpose of the systematic review and meta-analysis was to assess whether there was significant association between HS and psoriasis.

Methods

On June 01, 2022, we appraised 2,795 articles from databases including PubMed, Web of Science and Embase. Search syntaxes were based on 'hidradenitis suppurativa' or 'acne inversa' with "psoriasis", "comorbidities" or 'epidemiology'. Synonyms were determined based on MeSH terms and Emtree. Observational results that evaluated the odds ratio for people with hidradenitis suppurativa who had psoriasis were extracted for qualitative synthesis.

Results

After the selection process of the initial 2,795 studies, ten observational studies, including 3 cohort studies, 1 case-control study, and 6 cross-sectional studies, were extracted for critical appraisal. Based on the integration of 7 studies (with more than 560,000 participants included), people with hidradenitis suppurativa had a higher risk of having psoriasis, with a 2.67-fold risk (95% CI, 1.84, 3.87). The association remained in the sensitivity analyses utilizing strict adjustment models. In the analysis that only included studies with a similar study design and adjustments in obesity-related factors, the risk of people with hidradenitis suppurativa having psoriasis was 3.24 (95% CI, 2.27, 4.62). In male patients with HS, the risk of having psoriasis was 4.30-fold higher than male patients without HS (95% CI, 2.37, 7.78). Likewise, in an analysis including 3 cross-sectional studies, the risk of female HS patients having psoriasis was 3.94-fold higher than female HS-free patients (95% CI, 2.34, 6.63).

Conclusions

The co-occurrence of hidradenitis suppurativa and psoriasis can greatly increase the burden of the disease. Psoriasis could be one of the critical comorbidities of hidradenitis suppurativa and should be recommended for future screening and follow up. The association between the two diseases should be kept in mind in managing hidradenitis suppurativa patients. More prospective studies are needed to establish the true magnitude of the association between psoriasis and hidradenitis suppurativa.

Phenotype Algorithms to Identify Hidradenitis Suppurativa Using Real-World Data: Development and Validation Study

BACKGROUND

Hidradenitis suppurativa (HS) is a potentially debilitating, chronic, recurring inflammatory disease. Observational databases provide opportunities to study the epidemiology of HS.

OBJECTIVE

This study's objective was to develop phenotype algorithms for HS suitable for epidemiological studies based on a network of observational databases.

METHODS

A data-driven approach was used to develop 4 HS algorithms. A literature search identified prior HS algorithms. Standardized databases from the Observational Medical Outcomes Partnership (n=9) were used to develop 2 incident and 2 prevalent HS phenotype algorithms. Two open-source diagnostic tools, CohortDiagnostics and PheValuator, were used to evaluate and generate phenotype performance metric estimates, including sensitivity, specificity, positive predictive value (PPV), and negative predictive value.

RESULTS

We developed 2 prevalent and 2 incident HS algorithms. Validation showed that PPV estimates were highest (mean 86%) for the prevalent HS algorithm requiring at least two HS diagnosis codes. Sensitivity estimates were highest (mean 58%) for the prevalent HS algorithm requiring at least one HS code.

CONCLUSIONS

This study illustrates the evaluation process and provides performance metrics for 2 incident and 2 prevalent HS algorithms across 9 observational databases. The use of a rigorous data-driven approach applied to a large number of databases provides confidence that the HS algorithms can correctly identify HS subjects.

Comorbidities in Patients with Vitiligo: A Systematic Review and Meta-Analysis

Vitiligo has been reported to be associated with a variety of diseases, but it has not been systematically reviewed. Therefore, we aimed to identify prevalent diseases in patients with vitiligo and quantify their associations compared with those in healthy controls. A comprehensive search of MEDLINE and EMBASE from the inception to June 2022 was conducted. Observational studies on prevalent diseases in patients with vitiligo compared with those in healthy controls were included, whereas studies limited to pediatrics or providing only laboratory results were excluded. A total of 78 studies were eligible for analyses. Patients with vitiligo showed higher risks of having comorbid autoimmune and connective tissue diseases, including alopecia areata (OR = 2.63, 95% confidence interval [CI] = 2.50‒2.78), discoid lupus erythematosus (OR = 2.54, 95% CI = 1.74‒3.72), Sjogren's syndrome (OR = 2.50, 95% CI = 1.98‒3.16), myasthenia gravis (OR = 2.30, 95% CI = 1.74‒3.02), systemic lupus erythematosus (OR = 1.96, 95% CI = 1.52‒2.52), and rheumatoid arthritis (OR = 1.82, 95% CI = 1.55‒2.15). Thyroid diseases, diabetes mellitus, metabolic syndrome, sensorineural hypoacusis, and ophthalmic abnormalities were also more prevalent in patients with vitiligo. In conclusion, vitiligo is associated with various systemic diseases. Physicians should evaluate and manage potential comorbid conditions in patients with vitiligo.

Hidradenitis Suppurativa: The Influence of Gender, the Importance of Trigger Factors and the Implications for Patient Habits

Hidradenitis suppurativa (HS) is a debilitating, chronic, inflammatory skin disease primarily affecting apocrine gland-rich areas of the body. On the one hand, the presence of triggering factors-some identified, others only hypothesized-may initiate or perpetuate the pathogenic process of HS. In addition to cigarette smoking and diet, other trigger factors, including choice of clothing, are frequently observed in clinical practice. On the other hand, the presence of disease may influence habits of HS patients. Indeed, high incidences of sexual and sleep impairment have been reported in these patients. Consequently, alcohol and substance abuse may be a coping strategy for the emotional and psychological disease burden. Furthermore, a greater awareness of gender differences in HS may be important for dermatologists in their own clinical practice (i.e., pregnancy and breastfeeding). Consequently, in this loop interaction, comprehensive knowledge of all factors involved is crucial for the management of HS patients. Thus, the objective of this review is to (i) discuss the influence of gender on HS, (ii) summarize the most frequent triggering factors of HS and (iii) analyze the impact of HS on patient habits.

Comorbid diseases of hidradenitis suppurativa: a 15-year population-based study in Olmsted County, Minnesota, USA

BACKGROUND

Like other chronic, inflammatory skin disorders, hidradenitis suppurativa (HS) is increasingly recognized to be associated with various medical disorders.

OBJECTIVE

Using the Rochester Epidemiology Project (REP), we sought to conduct the first American population-based study examining the association between HS and various comorbid conditions.

METHODS

From the REP database, we identified patients diagnosed with HS from 2003 through 2018 who were residents of Olmsted County, Minnesota, USA, along with age- and gender-matched controls. The frequency of a wide variety of comorbid conditions was compared between the groups.

RESULTS

A total of 1160 patients with HS were identified during the study period. Compared with age- and gender-matched controls, patients with HS had a significantly higher frequency of several medical conditions, including depression, anxiety, hyperlipidemia, acne conglobata, dissecting cellulitis, pilonidal cysts, polycystic ovary syndrome, diabetes, chronic kidney disease, psoriasis, atopic dermatitis, obesity, and disordered substance use, among others.

LIMITATIONS

Our study was limited by its retrospective design.

CONCLUSIONS

Providers caring for patients with HS should consider these results, along with those of similar studies, and obtain a thorough history, comprehensive physical examination, and, potentially, laboratory testing and referral to other specialists.

Epidemiology of Hidradenitis Suppurativa: Current Status

Purpose of Review

This review aimed to provide a comprehensive and current state of art about epidemiology and clinical aspects of the HS.

Recent Findings

Our search yielded 17 articles that included studies that showed a prevalence range from 0.00033 to 1.4%. Incidence data is limited. HS is more prevalent in women than in men. The highest prevalence is found in the third and fourth decade of life. The most frequent localizations are the inguinal, axillary, and perianal regions. There are associations between HS and obesity (OR 2.09), hypertension (OR 1.84), and dyslipidemia (OR 4.06), among others.

Summary

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by occlusion of hair follicles as a primary pathogenic factor. It affects areas of the body with apocrine glands, predominantly in the axillary, inguinal, intermammary, and anogenital regions. Clinically, its manifestations vary from inflammatory nodules and abscesses to the formation of sinus tracts and scarring. HS used to be considered a disorder of apocrine glands; today, it is considered a disease of the pilosebaceous unit associated with an immune imbalance in a genetically predisposed individual, thus linked to other autoimmune diseases.

Predictors of sleep disordered breathing in children with Down syndrome: a systematic review and meta-analysis

Children with Down syndrome are at increased risk of sleep disordered breathing (SDB). SDB is associated with significant morbidity including neurocognitive impairment, cardiometabolic disease and systemic inflammation. The identification of clinical markers that may predict SDB is critical in facilitating early diagnosis and treatment, and ultimately, preventing morbidity. The objective of this systematic review was to identify predictors of SDB in patients with Down syndrome. A search was conducted using MEDLINE, Embase, the Cochrane Central Register of Controlled Trials and the Cumulative Index to Nursing and Allied Health Literature. A meta-analysis was performed according to the Meta-analyses of Observational Studies in Epidemiology checklist. Our review of the literature identified inconsistent associations between a variety of variables and SDB in children with Down syndrome, although the quality of evidence was poor. Meta-analysis of age and sex identified that children with OSA were older than those without OSA, and there was a similar risk of OSA in males and females, although risk favoured males. Currently, the American Academy of Pediatrics guidelines recommend that children with Down syndrome undergo polysomnography by the age of 4 years. Our review supports the recommendation for routine screening of children with Down syndrome. However, results from our meta-analysis suggest a need for longitudinal screening to diagnose children who may develop SDB as they get older.

This review identified several predictors of sleep disordered breathing (SDB) in children with Down syndrome. Meta-analysis identified older age as a predictor. This supports routine longitudinal screening of all children with Down syndrome for SDB.https://bit.ly/3KGnqFK

Population-based study for the comorbidities and associated factors in Ménière's disease

To date, no study has reported the objective metabolic laboratory findings worldwide or the comorbidities for Ménière’s disease (MD) using a population-based design in Asian populations. The aim of this study was to investigate the comorbidities and associated factors for MD using the Korean National Health Insurance Service database. This retrospective population-based study was conducted using a data from the National Sample Cohort database from 2009 to 2015. We only enrolled patients whose records showed a prescription for MD medicine and audiometry findings as well as an appropriate diagnostic code. We also included a matched cohort without MD who were enrolled randomly and matched for sex, age, year of diagnosis, income level, and residential area with the MD group with a ratio of 10:1. We evaluated comorbidities including autoimmune, allergic, metabolic diseases and cancer and the health screening data including general characteristics (height, weight, waist circumference, body mass index, and blood pressure), laboratory findings (fasting glucose, cholesterol, triglyceride, high-density lipoproteintryglyceride (HDL) cholesterol, low-density lipoproteintryglyceride cholesterol, hemoglobin, creatinine, aspartate aminotransferase and alanine aminotransferase, and gamma-glutamyltrans- peptidase (rGT)), and general health behaviors (smoking, alcohol, and exercise) of the MD group, and compared these characteristics with those of the MD-free control group. A total of 2,013 and 20,130 participants were included in the MD and MD-free control groups (1,640 and 15,458 for health screening data). We found the increase in incidence of allergic rhinitis and allergic asthma, decrease in systolic blood pressure, HDL cholesterol, and rGT, and less frequent alcohol consumption and less prevalent smoking in the MD group. No significant differences were observed between the groups in the incidence of autoimmune diseases, and cerebro- and cardiovascular disease as well as health screening data and objective laboratory findings. Inconsistence with published studies, the results of this study suggest that the autoimmunity and metabolic disorder, and skeletal growth might not be associated with the onset of MD. Another well-designed study for other races will be needed to the generalization of this study results.

ALA-iPDT for follicular occlusion tetrad concomitant with pachyonychia congenital type Ⅱ and ankylosing spondylitis

The follicular occlusion tetrad is a complex dermatologic syndrome which can concomitant with other diseases. The case reported a young male patient suffer from follicular occlusion tetrad (acne conglobata, hidradenitis suppurativa, dissecting cellulitis of the scalp, and pilonidal sinuses) concomitant with pachyonychia congenital type Ⅱ (thickened nails, palmoplantar keratoderma, multiple cysts) and ankylosing spondylitis (lumbago, human leukocyte antigen-B27 positive). The genetic analysis showed the KRT17 gene mutation on exon 1 (c.T284C) supports the diagnosis. Whereupon, a comprehensive therapy scheme of 5-aminolevulinic acid-mediated interstitial photodynamic therapy (ALA-iPDT) combined surgery and drug is tried and worked. This case reports a rare condition and propose a therapeutic option that may work.

Risks of Comorbidities in Patients With Palmoplantar Pustulosis vs Patients With Psoriasis Vulgaris or Pompholyx in Korea

Importance

Palmoplantar pustulosis (PPP) has been reported to be accompanied by systemic conditions. However, the risks of comorbidities in patients with PPP have rarely been evaluated.

Objective

To assess the risks of comorbidities in patients with PPP compared with patients with psoriasis vulgaris or pompholyx.

Design, Setting, and Participants

This nationwide population-based cross-sectional study used data from the Korean National Health Insurance database and the National Health Screening Program collected from January 1, 2010, to December 31, 2019. Data were analyzed from July 1, 2020, to October 31, 2021. Korean patients diagnosed with PPP, psoriasis vulgaris, or pompholyx who visited a dermatologist between January 1, 2010, and December 31, 2019, were enrolled.

Exposures

Presence of PPP.

Main Outcomes and Measures

The risks of comorbidities among patients with PPP vs patients with psoriasis vulgaris or pompholyx were evaluated using a multivariable logistic regression model.

Results

A total of 37 399 patients with PPP (mean [SD] age, 48.98 [17.20] years; 51.7% female), 332 279 patients with psoriasis vulgaris (mean [SD] age, 47.29 [18.34] years; 58.7% male), and 365 415 patients with pompholyx (mean [SD] age, 40.92 [17.63] years; 57.4% female) were included in the analyses. Compared with patients with pompholyx, those with PPP had significantly higher risks of developing psoriasis vulgaris (adjusted odds ratio [aOR], 72.96; 95% CI, 68.19-78.05; P < .001), psoriatic arthritis (aOR, 8.06; 95% CI, 6.55-9.92; P < .001), ankylosing spondylitis (aOR, 1.91; 95% CI, 1.61-2.27; P < .001), type 1 diabetes (aOR, 1.33; 95% CI, 1.16-1.52; P < .001), type 2 diabetes (aOR, 1.33; 95% CI, 1.29-1.38; P < .001), Graves disease (aOR, 1.25; 95% CI, 1.11-1.42; P < .001), Crohn disease (aOR, 1.63; 95% CI, 1.11-2.40; P = .01), and vitiligo (aOR, 1.87; 95% CI, 1.65-2.12; P < .001) after adjusting for demographic covariates. The risks of ankylosing spondylitis (aOR, 1.37; 95% CI, 1.16-1.62; P < .001) and Graves disease (aOR, 1.40; 95% CI, 1.23-1.58; P < .001) were significantly higher among patients with PPP vs psoriasis vulgaris. However, the risks of psoriatic arthritis (aOR, 0.54; 95% CI, 0.47-0.63; P < .001), systemic lupus erythematosus (aOR, 0.67; 95% CI, 0.46-0.97; P = .04), Sjögren syndrome (aOR, 0.70; 95% CI, 0.50-0.96; P = .03), systemic sclerosis (aOR, 0.29; 95% CI, 0.11-0.77; P = .01), vitiligo (aOR, 0.53; 95% CI, 0.47-0.60; P < .001), and alopecia areata (aOR, 0.88; 95% CI, 0.81-0.95; P = .001) were significantly lower among those with PPP vs psoriasis vulgaris.

Conclusions and Relevance

The results of this cross-sectional study suggest that patients with PPP have an overlapping comorbidity profile with patients with psoriasis vulgaris but not patients with pompholyx. However, the risks of comorbidities among patients with PPP may be substantially different from those among patients with psoriasis vulgaris.

Surgical Treatment of Vitiligo

Vitiligo is described as a dermatological condition characterized by pigmentation disorders in both the skin and mucous membranes. Clinically, this disease is characterized by the presence of well-defined white areas of various shapes and sizes, which are a manifestation of a reduced number of melanocytes. Due to the fact that vitiligo can be a significant cosmetic problem for patients, a number of methods are currently available to help fight for a better skin appearance. If all the available non-invasive procedures turn out to be ineffective, surgery can help, which is a very good alternative in the case of difficult-to-treat but stable changes. Both the development of new techniques and modifications to the already available treatment of cell and tissue transplantation give hope to numerous patients around the world. The effectiveness of a particular method is determined by its appropriate selection depending on the lesions undergoing therapy. Each form of surgical intervention has its advantages and disadvantages, which, along with the location or size of the treated hypopigmentation area, should be analyzed by a doctor and discussed with their patient. This article is an overview of the currently available methods of surgical treatment of vitiligo and a comparison of their pros and cons.

Insights into hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, debilitating, inflammatory skin disorder with a prevalence of around 1% and a profound impact on patients' quality of life. Characteristic lesions such as inflammatory nodules, abscesses, and sinus tracts develop in the axillae, inguinal, and gluteal areas, typically during or after puberty. A complex interplay of genetic predisposition, hormonal factors, obesity, and smoking contributes to development and maintenance of the disease. HS is considered to arise from an intrinsic defect within the hair follicle, leading to follicular plugging, cyst formation, and subsequent rupture that in turn induce an acute inflammatory response characterized by elevated levels of IL-1β, IL-17, and TNF. Over time, acute lesions transition into chronic disease, with active draining sinus tracts accompanied by extensive fibrosis. HS is associated with other immune-mediated inflammatory diseases, metabolic and cardiovascular disorders, and psychiatric comorbidities. Treatment of HS often requires a combination of antibiotic or immunosuppressing therapies and surgical intervention. Nonetheless, the currently available treatments are not universally effective, and many drugs, which are often repurposed from other inflammatory diseases, are under investigation. Studies into the early stages of HS may yield treatments to prevent disease progression; yet, they are hampered by a lack of appropriate in vitro and animal models.

Hidradenitis suppurativa: racial and socioeconomic considerations in management

Studies on hidradenitis suppurativa (HS) have found an increased prevalence of HS in skin of color and lower socioeconomic status patients, although the reasons for these differences are unclear. Demographic and therapeutic studies of HS originate primarily from developed Western countries, and data from low- and medium-income countries (LMIC) remain comparatively limited. In this review paper, we discuss differences in clinical presentation and comorbidities between racial and socioeconomic subpopulations and describe the genetic, biomedical, psychosocial, and ecological factors that may explain the associations between HS and skin of color and socioeconomic status. We highlight biomedical treatment considerations for LMIC including cost effective and less complex treatment strategies. We touch on population-based strategies to address the social determinants of health in HS management and discuss additional challenges arising from the COVID-19 pandemic.

A Novel NCSTN Mutation in a Three-Generation Chinese Family with Hidradenitis Suppurative

Objective

Hidradenitis suppurativa (HS) is a rare autosomal dominant condition characterized by inflamed nodules, cysts, deep abscesses, draining sinuses in the axillae, inguinal, and anogenital regions. Mutations in the NCSTN gene have been perceived to be responsible for the major underlying changes in the disorder. The purpose of this study is to identify a novel gene mutation in a Chinese family with HS.

Methods

A Chinese family with HS present was investigated. The proband had manifested with multiple draining sinuses on the posterior neck, chest, bilateral axillae, and perineal regions. DNA was isolated from the peripheral blood of the family members. The encoding exons with introns of the NCSTN gene were analyzed by polymerase chain reactions (PCR) and direct DNA sequencing. Sanger sequencing was performed to confirm the next-generation sequencing results and to analyze each mutation's familial segregation. Furthermore, the identified mutation was localized onto a 3D structure model using the DeepView Swiss-PdbViewer 4.1 software.

Results

In this family comprising 10 HS patients, one novel mutation of the NCSTN gene was identified, involving a deletion mutation (c.447delC(p.N150Ifs∗52)) in the NCSTN gene resulting in a frameshift and the new formation of a hydrogen bond.

Conclusion

Our study reports the identification of a novel mutation that causes familial HS and could expand the spectrum of mutations in the γ-secretase genes underlying HS.

Real-world safety and effectiveness of adalimumab in patients with hidradenitis suppurativa: 12-week interim analysis of post-marketing surveillance in Japan

Hidradenitis suppurativa (HS) is a painful chronic skin disease characterized by abscesses, nodules, and tunnels in the skin. Adalimumab, a monoclonal antibody against tumor necrosis factor‐α, is approved for the treatment of HS in Europe, the USA, and Japan. This multicenter, open‐label, post‐marketing, observational study (ClinicalTrials.gov: NCT03894956) evaluated the safety and effectiveness of adalimumab in routine clinical practice in Japan (March 2019–May 2021). Patients with HS were treated with s.c. doses of adalimumab according to the dosage described in the package insert. The primary end‐point was safety (data cut‐off, December 2020). Secondary end‐points assessed effectiveness, including HS Clinical Response (HiSCR), skin pain, Dermatology Life Quality Index (DLQI), and C‐reactive protein (CRP). Here, we report 12‐week interim effectiveness results. A total of 84 eligible patients from 65 sites were enrolled; 83 patients were included in this analysis. Mean age was 42.0 years, mean body mass index was 26.9 kg/m², 78.3% of patients were male, 61.4% had Hurley stage III disease, 39.8% had a disease duration ≥10 years, and 7.2% had a family history of HS. The most common affected sites were the axilla (60.2%), buttocks (59.0%), and the inguinal and femoral regions (47.0%). Mean abscess and inflammatory nodule count was 13.0 (standard deviation, 12.0). Among patients with a comorbidity (57.8%), the most common were diabetes mellitus, hypertension, and chronic kidney disease. No patient reported a serious infection or any safety event of special interest. One patient died from a serious adverse event of cardiac failure unrelated to adalimumab. At week 12, 57.4% of patients achieved HiSCR, and significant reductions from baseline in skin pain, DLQI (both p < 0.0001), and CRP (p = 0.0029) were observed. These results support the administration of adalimumab as a well‐tolerated and effective treatment for Japanese patients with HS in real‐world clinical practice.

New Insights in Hidradenitis Suppurativa from a Population-based Dutch Cohort: Prevalence, Smoking Behaviour, Socioeconomic Status and Comorbidities

Background

Hidradenitis suppurativa (HS) is a chronic autoinflammatory skin condition and is associated with several comorbidities. Previous studies report variable prevalence rates of HS, depending on the methodology. However, the exact prevalence remains unknown.

Objectives

To estimate the prevalence of HS in a large population‐based cohort in the Northern Netherlands, and to compare patients with HS to the general population, investigate characteristics and identify potential associated comorbidities.

Methods

Data were collected through a cross‐sectional survey‐based study within the Lifelines Cohort Study (n = 167 729), based on the general population located in the Northern Netherlands. A digital self‐reported questionnaire was developed consisting of validated questions for determining HS.

Results

Among 56 084 respondents, the overall prevalence of HS was 2.1% [95% confidence interval (CI) 2.0–2.2]. The respondents with HS had lower socioeconomic status than the controls (P < 0.001) and more frequently currently smoked (P < 0.001). Several new significant associations in patients with HS were revealed, such as fibromyalgia (OR 2.26, 95% CI 1.64–3.11), irritable bowel syndrome (OR 1.63, 95% CI 1.18–2.26), chronic fatigue syndrome (OR 1.72, 95% CI 1.06–2.78) and migraine (OR 1.48, 95% CI 1.11–1.96). Fibromyalgia and chronic fatigue syndrome remained significantly associated with HS in the multivariate analysis after adjusting for age, sex, body mass index, smoking status and socioeconomic status.

Conclusions

Our study showed a higher prevalence of HS in the Northern Netherlands compared with the overall estimated prevalence of 1% and identified several new associated comorbidities.

Characterization of comorbidity heterogeneity among 13,667 patients with hidradenitis suppurativa

Hidradenitis suppurativa (HS) is a chronic, inflammatory skin disorder characterized by recurrent abscesses in the groin and flexural areas. HS is associated with a wide range of comorbidities that complicate the disease course. Although these comorbidities have been well described, it remains unclear how these comorbidities coassociate and whether comorbidity profiles affect disease trajectory. In addition, it is unknown how comorbidity associations are modulated by race and sex. In this comprehensive analysis of 77 million patients in a large US population–based cohort, we examined coassociation patterns among HS comorbidities and identified clinically relevant phenotypic subtypes within HS. We demonstrated that these subtypes not only differed among races, but also influenced clinical outcomes as measured by HS-related emergency department visits and cellulitis. Taken together, our findings provide key insights that elucidate the unique disease trajectories experienced by patients with HS and equip clinicians with a framework for risk stratification and improved targeted care in HS.

Incidence, prevalence, and predictors of inflammatory arthritis in patients with hidradenitis suppurativa: a systematic review and meta-analysis

An increasing amount of evidence has emerged suggesting that hidradenitis suppurativa (HS) is associated with inflammatory arthritis. This study reviewed the incidence, prevalence, and predictors of inflammatory arthritis in patients with HS. A comprehensive literature search was conducted in CINAHL, Embase, and Medline from inception to February 14, 2020. Articles were included in the review if they provided data on disease epidemiology or predictors of adult or pediatric HS patients with comorbid inflammatory arthritis. There are no validated diagnostic criteria for HS, thus we considered patients as having HS if they had at least one diagnostic code in a hospital or claims database or a diagnosis of HS/inflammatory arthritis in a medical record. The same criteria were used to confirm presence of inflammatory arthritis. We identified an increased incidence of rheumatoid arthritis (RA), ankylosing spondylitis (AS), and psoriatic arthritis (PsA) in HS patients when compared with estimates in the general population. We identified a relatively high prevalence of RA, spondyloarthritis (SpA), and PsA in HS patients when compared with estimates in the general population. There was evidence to suggest that patients who are younger than 30, male, have severe HS, or are taking infliximab or adalimumab (which may also be confounded by HS disease severity) may be at greater risk for specific subtypes of inflammatory arthritis. However, further data are needed to confirm these associations. The increased incidence and prevalence of inflammatory arthritis within HS patients underscore the need for increased awareness and interdisciplinary partnership within rheumatology and dermatology.

Hidradenitis suppurativa and rheumatoid arthritis: evaluating the bidirectional association

Despite some common pathogenic themes, the association of hidradenitis suppurativa (HS) and rheumatoid arthritis (RA) has been poorly investigated. We aimed to evaluate the bidirectional association between HS and RA. A population-based study was conducted to compare HS patients (n = 6779) with age-, sex- and ethnicity-matched control subjects (n = 33,260) with regard to the incidence of new-onset and the prevalence of preexisting RA. Adjusted hazard ratios (HRs) and adjusted odds ratios (ORs) were estimated. The prevalence of preexisting RA was greater among patients with HS relative to controls (0.5% vs 0.3%. respectively; p = 0.019). The odds of being diagnosed with HS were 1.6-fold higher in patients with a history of RA (fully-adjusted OR, 1.66; 95% CI, 1.11–2.49; p = 0.014). The incidence rate of new-onset RA was estimated at 4.3 (95% CI, 2.5–6.8) and 2.4 (95% CI, 1.8–3.2) cases per 10,000 person-years among patients with HS and controls, respectively. The risk of RA was comparable between patients with HS and controls (fully-adjusted HR, 1.45; 95% CI, 0.77–2.72; p = 0.249). Compared to other patients with HS, those with HS and comorbid RA were older, had a higher prevalence of diabetes mellitus, hypertension, and hyperlipidemia, and had a comparable risk of all-cause mortality. In conclusions, a preexisting diagnosis of RA predisposes individuals to develop HS. Clinicians managing patients with HS and RA should be aware of this association. Further research is required to delineate the underlying pathomechanism of this observation.

Evidence of gene-gene interaction in Hidradenitis suppurativa - A nationwide register study of Danish twins

BACKGROUND

Hidradenitis suppurativa (HS) is a recurrent inflammatory skin disease that, apart from rare causative loss-of-function mutations, has a widely unknown genetic aetiology. Our objective was to estimate the relative importance of genetic and environmental factors underlying HS susceptibility.

METHODS

Through the Danish Twin Registry and the Danish National Patient Registry we joined information on zygosity with that of HS status. HS cases were identified by International Code of Diseases 8 (705.91) and 10 (L73.2). Heritability was assessed by the classic biometric model and the possibility of gene-gene interaction through the multi-locus modeling approach.

RESULTS

Amongst 100,044 registered twins, we found 170 twins (from 163 pairs) diagnosed with HS. The seven concordant pairs were all monozygotic, and monozygotic twins had a casewise concordance rate of 28% (95% CI: 7%; 49%), corresponding to a familial risk of 73 (95% CI 13; 133) times that of the background population. The biometrical modelling suggested a heritability of 0.80 (95% CI 0.67; 0.93), and the multilocus index estimate was 230 (95% CI: 60; 400). This is highly indicative of gene-gene interactions, with the possibility of up to six interacting loci.

CONCLUSION

This twin study is substantially larger, and employs a more valid phenotype than prior studies. Genetics account for the majority of the HS susceptibility, and HS is most likely caused by gene-gene interactions rather than monogenetic mutations or solely additive genetic factors. New approaches aimed at assessing potential interactions at a SNP-SNP level should be implemented in future HS genome-wide association studies.

[Epidemiology, patient quality of life, and treatment costs of hidradenitis suppurativa/acne inversa]

Hidradenitis suppurativa/acne inversa (HS) is associated with numerous and relevant restrictions on the quality of life for those affected and their relatives. The exact prevalence of HS varies significantly across studies, but it is likely to be higher than suggested in previous publications. HS care is associated with high costs for the healthcare system and for those affected. The introduction of biologic therapy has led to additional costs, but also to considerable additional benefits in terms of care. In view of the complexity of diagnostics and therapy, there is a particular need for optimized care concepts in order to reduce the burden on those affected, their relatives and the healthcare system.

Hidradenitis suppurativa in South-East Asia and East Asia

Hidradenitis suppurativa (HS) in South-East Asia and East Asia shows distinct clinical, environmental, physiological and likely genetic differences compared with the West. A male predominance is present, which may be due to differences in smoking habits. Involvement of the buttocks is common in East Asian patients, while the axillae are most commonly affected in South-East Asian patients. Metabolic comorbidities are prevalent in South-East Asian and East Asian HS patients. A family history of HS is less common than noted in Western populations. Asian ethnic subgroups deserve further study.

Hidradenitis suppurativa in East and Southeast Asian populations: a systematic review and meta-analysis

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that presents with recurrent inflammatory nodules and draining tunnels in the skin. Most HS studies have focused on Western populations, and the understanding of how HS characteristics differ in specific Asian ethnicities is poor. We conducted the first systematic review and meta-analysis to characterize HS patients from East and Southeast Asia. PubMed, Embase, and Ovid MEDLINE databases were searched from inception to June 12, 2020. English-language case-series, cross-sectional, observational, and randomized controlled trial studies investigating HS in East and Southeast Asian populations were screened by titles, abstracts, and articles in duplicate. Of 136 citations, 10 studies were included in the meta-analysis. Data on gender distribution, lesion distribution in the axilla and gluteal regions, and family history were extracted in duplicate. A random effects model was used for the meta-analysis. A total of 30,125 HS patients were included in the analysis. Most patients were male (66%, 95% CI = 60-72%). About half of Asian patients with HS develop lesions in the axilla (52%, 95% CI = 33-72%) and the buttocks (48%, 95% CI = 38-57%). Only a small subset had positive family history of HS (5%, 95% CI = 2-8%). We report an up-to-date characterization of HS in East and Southeast Asian populations and highlight differences in their Western counterparts. These results will hopefully improve understanding for how HS may manifest, lead to more personalized treatments for Asian patients with HS, and usher in a proper patient-centered approach to treating the disease.

Thematic synthesis of the experiences of people with hidradenitis suppurativa: a systematic review

BACKGROUND

Although hidradenitis suppurativa (HS) is known to affect quality of life, little summative knowledge exists on how HS impacts people living with the condition.

OBJECTIVES

To synthesize experiences of people with HS within published qualitative research.

METHODS

Searches on databases MEDLINE, PsycINFO, Embase and CINAHL were conducted on 17 April 2020. Two independent reviewers screened 5512 publications. Study quality was assessed using the National Institute for Health and Care Excellence quality appraisal checklist for qualitative studies. Thematic synthesis generated descriptive and analytic themes.

RESULTS

Fourteen studies were included: four studies fulfilled most quality criteria, eight fulfilled some quality criteria, and two fulfilled few quality criteria. There were three final themes. (i) Putting the brakes on life. The physical, psychological and social consequences of HS resulted in people missing out on multiple life events. This could have a cumulative effect that influences the trajectory of someone's life. (ii) A stigmatized identity: concealed and revealed. People try to conceal their HS, visually and verbally, but this results in anticipation and fear of exposure. Social support and psychological acceptance helped people cope. Connecting to others with HS may have a specific role in preserving a positive self-identity. (iii) Falling through the cracks. Delayed diagnosis, misdiagnosis and lack of access to care were reported. People felt unheard and misunderstood by healthcare professionals, and healthcare interactions could enhance feelings of shame.

CONCLUSIONS

There need to be improvements to clinical care to allow people with HS to live their life more fully.

Association between Hidradenitis Suppurativa and Inflammatory Arthritis: A Systematic Review and Meta-Analysis

BACKGROUND

Several studies report a high prevalence of inflammatory arthritis among hidradenitis suppurativa (HS) patients.

OBJECTIVES

To study the association between HS and inflammatory arthritis.

METHODS

The systematic review and meta-analysis were performed according to the PRISMA guidelines to identify the association between HS and inflammatory arthritis, spondyloarthritis, ankylosing spondylitis (AS), and rheumatoid arthritis (RA).

RESULTS

Seven studies were entered in the analysis, with 200,361 HS patients and 385,599 controls. Pooled analysis illustrated a significantly increased risk of inflammatory arthritis in HS patients compared to controls (odds ratio [OR] 3.44; 95% confidence interval [CI] 1.92-6.17). There was also a statistically significant association between HS and spondyloarthritis (OR 2.10; 95% CI 1.40-3.15), and between HS and AS (OR 1.89; 95% CI 1.14-3.12). Moreover, pooled analysis showed a statistically significant association between HS and RA (OR 1.96; 95% CI 1.28-2.98).

CONCLUSIONS

Our findings show that HS patients have a 3-fold increased risk of developing inflammatory arthritis. HS patients are specifically at a higher risk for spondyloarthritis, its subtype AS, and RA.

Epidemiology of hidradenitis suppurativa in Taiwan: A 14-year nationwide population-based study

Hidradenitis suppurativa (HS), also called acne inversa, is an inflammatory skin disease, which causes HS patients to suffer from recurrent symptoms and severe comorbidities. The aim of this article was to provide evidence on the epidemiology of HS in Taiwan through a retrospective population-based cohort study. The patients with International Classification of Diseases, Ninth Revision, Clinical Modification code 705.83 and Anatomical Therapeutic Chemical codes for HS treatments from 2000 to 2013 in the National Health Insurance Research Database, which covers 99.9% Taiwanese residents, were enrolled in this 14-year nationwide population-based cohort study. The age- and sex-standardized prevalence, incidence, and the prescription pattern for HS were analyzed. The annual percent change (APC) was used to estimate the trend of prevalence and incidence of HS from 2000 to 2013. During 2000-2013 in Taiwan, the 14-year period prevalence rate was 185.6/100 000 (95% confidence interval [CI], 177.3-194.3) with an APC of -2.96% (95% CI, -1.73 to -4.17) and the mean annual adjusted incidence rate from 2001 to 2013 was 11.8/100 000 (95% CI, 11.2-12.5) with an APC of -4.65% (95% CI, -3.32 to -5.95). Female : male ratio was 0.92 and the most common onset age was 15-24 years. Major treatments were systemic corticosteroids, systemic antihistamines, systemic antibiotics, and topical antibiotics. An increasing tendency of using systemic antibiotics was noted. In Taiwan, decreasing incidence and prevalence of HS was shown during 2000-2013. Relatively lower incidence and prevalence were noted compared to Western countries. Male predominance was revealed, and the use of systemic antibiotics became the mainstream in treatment for HS.

Assessment of Overall and Specific Cancer Risks in Patients With Hidradenitis Suppurativa

Importance

Large population-based studies investigating the risks of overall and specific cancers among patients with hidradenitis suppurativa (HS) are limited.

Objective

To assess the overall and specific cancer risks in patients with HS compared with the risks in patients without HS in the Republic of Korea.

Design, Setting, and Participants

A nationwide population-based cohort study, using the Korean Health Insurance Review and Assessment Service database was conducted over a 2-year period from January 1, 2007, to December 31, 2008. Individuals in the control group who were never diagnosed with HS or cancer during the washout period were randomly extracted and matched by age, sex, index year, and insurance type at a case-control ratio of 1:8, and patients with newly diagnosed HS between January 1, 2009, and December 31, 2017, were included. Follow-up data on incident cancer from January 1, 2009, to December 31, 2018, were included.

Main Outcomes and Measures

The overall and specific cancer incidence rates were calculated per 100 000 person-years in patients with HS and in the matched control cohort. The risk for cancers was assessed by multivariable Cox regression models in patients with HS compared with the matched control cohort.

Results

In total, 22 468 patients with HS and 179 734 matched controls were included in the study. The mean (SD) age was 33.63 (17.61) years and 63.7% of the participants in both groups were male. The adjusted hazard ratio (aHR) of overall cancer in patients with HS was 1.28 (95% CI, 1.15-1.42). Patients with HS had significantly higher risk for Hodgkin lymphoma (aHR, 5.08; 95% CI, 1.21-21.36), oral cavity and pharyngeal cancer (aHR, 3.10; 95% CI, 1.60-6.02), central nervous system cancer (aHR, 2.40; 95% CI, 1.22-4.70), nonmelanoma skin cancer (HR, 2.06; 95% CI, 1.12-3.79), prostate cancer (aHR, 2.05; 95% CI, 1.30-3.24), and colorectal cancer (aHR, 1.45; 95% CI, 1.09-1.93).

Conclusions and Relevance

In this study, HS appeared to be associated with a significantly increased risk of overall cancer as well as several specific cancers.

Comorbidity screening in hidradenitis suppurativa: Evidence-based recommendations from the US and Canadian Hidradenitis Suppurativa Foundations

Background:

Hidradenitis suppurativa (HS) is associated with comorbidities that contribute to poor health, impaired life quality, and mortality risk.

Objective:

To provide evidence-based screening recommendations for comorbidities linked to HS.

Methods:

Systematic reviews were performed to summarize evidence on the prevalence and incidence of 30 comorbidities in patients with HS relative to the general population. The screening recommendation for each comorbidity was informed by the consistency and quality of existing studies, disease prevalence, and magnitude of association, as well as benefits, harms, and feasibility of screening. The level of evidence and strength of corresponding screening recommendation were graded by using the Strength of Recommendation Taxonomy (SORT) criteria.

Results:

Screening is recommended for the following comorbidities: acne, dissecting cellulitis of the scalp, pilonidal disease, pyoderma gangrenosum, depression, generalized anxiety disorder, suicide, smoking, substance use disorder, polycystic ovary syndrome, obesity, dyslipidemia, diabetes mellitus, metabolic syndrome, hypertension, cardiovascular disease, inflammatory bowel disease, spondyloarthritis, and sexual dysfunction. It is also recommended to screen patients with Down syndrome for HS. The decision to screen for specific comorbidities may vary with patient risk factors. The role of the dermatologist in screening varies according to comorbidity.

Limitations:

Screening recommendations represent one component of a comprehensive care strategy.

Conclusions:

Dermatologists should support screening efforts to identify comorbid conditions in HS.