Background: Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition substantially impacting patients’ quality of life; the pathogenesis remains unclear, and treatment is complex and not yet standardized. Observational data are increasingly being used to evaluate therapeutics in “real-life” interventions, and the development of e-cohorts is offering new tools for epidemiological studies at the population level. Objective: The aim of this study was to describe the clinical characteristics and treatment history of HS participants in the Community of Patients for Research (ComPaRe) cohort and to compare these to other cohorts. Methods: We performed a cross-sectional study of the baseline data of HS participants in ComPaRe, an e-cohort of patients with chronic diseases. Data were collected using patient-reported questionnaires about clinical-dem­ographic aspects, quality of life, and treatment history. Results: A total of 396 participants (339 females, 57 males) were included (mean age 38 years); 83 (21%) had a family history of HS, 227 (57.3%) were current smokers, and 241 (60.9%) were overweight or obese. Most of the participants declared a Hurley stage II (n = 263, 66.4%) or III (n = 76, 20.3%). The breast was more frequently affected in women than men (37.5 vs. 5.3%, p < 0.0001), whereas the dorsal region was more frequently affected in men (39.5 vs. 10.9%, p < 0.0001). Increased disease stage was associated with obesity (25.9 vs. 33.8 vs. 51.3%, p = 0.02) and some HS localizations (genital [p < 0.005], pubis [p < 0.007], gluteal fold [p = 0.02], and groin [p < 0.0001]). The most frequently prescribed treatments were oral antibiotics (n = 362, 91.4%), especially amoxicillin-clavulanic acid and cyclins. Less than 10% of participants received biologics. Most of these results were consistent with previously published cohorts. Conclusion: Recruitment of participants by such a web platform can be a faster way to get relevant scientific data for a wide variety of patients that could be used for epidemiological studies and to evaluate therapeutics in “real-life” interventions.

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease characterized by the appearance of recurrent nodules and painful abscesses that progress to suppuration, fistulization, and scarring [1] and are mainly located in the body folds. Its prevalence had been estimated at 0.5–1% [2, 3]. Several factors, including insufficient knowledge and education of health care providers and the heterogeneity of clinical presentation, are likely to account for the delay in diagnosis and management of HS, often several years [4]. The pathophysiology remains poorly understood and the disease seems to be due to a genetic background [5, 6], with environmental factors, a role of hormones [7, 8], seemingly perturbations in skin [9‒11], and possibly gut dysbiosis [12] resulting in deregulated skin and systemic immune responses. Overweight and smoking can result in disease worsening [13, 14].

HS is associated with many comorbidities including metabolic syndrome, spondylarthropathies, inflammatory bowel disease, and depression and has a major impact on quality of life in moderate-to-severe forms [15‒19].

The therapeutic strategies for HS are based on a multidisciplinary approach including dermatology, surgery, nutrition, and psychiatry. Available therapies are frequently combined and include topical treatment, wound care, systemic antibiotics, hormonal treatment, biological agents, and surgery, including laser. The treatment choice depends mainly on disease severity and associated comorbidities. Although European and North American guidelines for HS have been published [20, 21], there is a lack of high-quality evidence to support management recommendations for HS, which are often based on expert opinion.

Observational data are increasingly being used to evaluate therapeutics, particularly in the context of complex “real-life” interventions [22]. Over the last decade, digital technologies have raised two major trends: (1) most communications now rely on digital technologies [23], and (2) the number of users is growing and very high [24] in large parts of the world [25], offering new tools for epidemiological studies at the population level. Likewise, numerous web applications have been developed in the past years to facilitate physician and patient interactions, and in line with this moving picture is the increasing development of e-cohorts in different disease settings [26]. E-cohorts are based on online recruitment and follow-up through the use of electronic questionnaires. Several online projects have shown that data collection for research via the Internet was feasible [27] and that the response rate was similar with e-mail studies [28]. For researcher, it allows to recruit large numbers of participants quicker as well as to reduce the costs associated with sending paper data and errors during transcription compared to a classic cohort.

The Community of Patients for Research (ComPaRe) is a French e-cohort of patients with chronic conditions. A specific e-cohort dedicated to HS, called HS ComPaRe, is nested in the ComPaRe e-cohort. We hypothesized that the sociodemographic and clinical characteristics of HS patients in this e-cohort would be comparable to those of previous classic cohorts designed differently. If our hypothesis is confirmed, this field could be a faster way to get relevant scientific data that could be used for epidemiological studies and to evaluate “real-life” interventions.

For further details, see the online supplementary material (see www.karger.com/doi/10.1159/000513447) (Fig. 1) [26, 29].

Fig. 1.

Flowchart of Materials and Methods. ComPaRe, Community of Patients for Research; HS, hidradenitis suppurativa.

Fig. 1.

Flowchart of Materials and Methods. ComPaRe, Community of Patients for Research; HS, hidradenitis suppurativa.

Close modal

Baseline Characteristics of the Participants (Tables 1, 2)

In June 2020, 37,502 patients were registered in ComPaRe, and 884 (2.4%) reported having HS; 396 (339 females, 57 males [sex ratio 6:1], mean [standard deviation] age 38 [10] years) completed the survey dedicated to HS (Fig. 1; Table 1). The diagnosis of HS was made by a dermatologist for 251 (63.4%) participants, by a surgeon for 97 (24.5%) participants, then by a general practitioner or another specialist. A total of 82 (20.7%) patients made their diagnosis themselves. The reported mean age at disease onset was 21.4 (8.3) years and at diagnosis 30.6 (10.3) years, with a mean diagnosis delay of 9.2 (9.2) years. In all, 83 (21%) participants had a family history of HS, 98 (24.7%) were overweight (body mass index [BMI] 25–29) and more than one-third (143 [36.1%]) were obese (BMI ≥30). A total of 227 (57.3%) were current smokers; only 64 (16.2%) declared never having smoked. Concerning education level, 109 (27.5%) had a bachelor’s degree or less. The data highlight the predominance of skin phototype II/III. Most participants reported moderate-to-severe disease: two-thirds of participants (263 [66.4%]) declared having Hurley stage II and (76 [20.3%]) stage III.

Table 1.

Baseline characteristics of patients with HS and by sex in the ComPaRe study cohort

 Baseline characteristics of patients with HS and by sex in the ComPaRe study cohort
 Baseline characteristics of patients with HS and by sex in the ComPaRe study cohort
Table 2.

Clinical characteristics of HS

 Clinical characteristics of HS
 Clinical characteristics of HS

Concerning comorbidities, 9 (2.8%) participants with diabetes and 15 (3.8%) with arterial hypertension showed cardiovascular disease risk; 26 (6.6%) had a diagnosis of depression. A total of 19 (4.8%) participants declared having a inflammatory bowel disease: 18 (4.5%) had Crohn’s disease and 1 (0.3%) had ulcerative colitis; 15 (3.8%) had a diagnosis of spondylarthritis.

In the past 6 months, the total number of flares was >6 for 72 (18.2%) participants, and 93 (23.5%) described a continuous disease without clear remission (Table 2). Painful boils were present in 375 (94.7%) participants, and 201 (52.3%) had suppuration at the time they completed the questionnaire. A total of 154 (38.9%) participants reported joint pain; about one-third reported inflammatory back pain and 80 (20.2%) alternating sciatica. Few participants reported chronic diarrhea (more than twice a day, 24 [6.1%]), bloody stools (61 [15.4%]), or anal fissure (79 [18.9%]).

Participants’ quality of life was highly affected by HS, as emphasized by the mean Dermatology Life Quality Index (DLQI) score of 13.7. More than half of the respondents (187/300 [62.3%]) reported at least one sick leave because of HS during the past year, 25/300 (8.3%) reported work disability, and 16/302 (5.3%) declared having been fired by their employer.

Treatments (Table 3)

More than half of the survey participants (n = 230, 58.1%) had been hospitalized because of HS (including outpatient surgery). Surgery for HS was reported by two-thirds of participants (n = 254) and ≥5 surgical interventions by 94 (37%) of these. Most participants used topical treatments: 370 (93.4%) used antiseptics and topical antibiotics such as fusidic acid cream.

Table 3.

Treatment history

 Treatment history
 Treatment history

A total of 362 (91.4%) participants received oral antibiotics, mainly amoxicillin-clavulanic acid (49.8%) and cyclins (45.2%). Only 34 (8.6%) participants had never received antibiotics. Other systemic treatments included zinc (n = 126, 31.8%), isotretinoin (n = 44, 11.1%), systemic corticosteroids (n = 40, 10.1%), and biologics (n = 38 [9.6%]: n = 22 [5.6%] with adalimumab, n = 13 [3.3%] with infliximab, n = 3 [0.8%] with ustekinumab). Three women (0.8%) declared using cyproterone acetate.

Most participants received analgesics (n = 288, 72.7%). Eight (2%) declared using anti-inflammatory drugs as analgesic treatment.

Characteristics by Sex (Table 1)

Age at diagnosis and diagnostic delay were significantly lower for women than men (29.9 vs. 34.6 and 9.0 vs. 10.4, respectively, p < 0.0001). Women and men did not differ in Hurley stage, smoking status, or BMI. The most affected areas were the axillary and groin regions in more than two-third of cases. The front of the body was significantly more involved in women, especially the breast (37.5 vs. 5.3%, p < 0.0001), pubis (59 vs. 43.9%, p = 0.03), and groin (89.4 vs. 68.4%, p < 0.0001). However, men presented more lesions on the back (38.6 vs. 10.9%, p < 0.0001), neck (36.8 vs. 14.2%, p < 0.0001), and behind the ears (42.1 vs. 25.4%, p < 0.01).

Characteristics by Hurley Stage (Table 4)

Hurley stage did not differ by sex, mean age, family history of HS, comorbidities, or smoking status. However, increasing disease stage was associated with obesity (25.9 vs. 33.8 vs. 51.3%, p = 0.02). On univariate analyses, increasing disease stage was associated with HS of the genitals (40.7 vs. 44.5 vs. 65.8%, p < 0.005), pubis (40.7 vs. 57.4 vs. 68.4%, p = 0.007), gluteal fold (25.9 vs. 44.2 vs. 48.7%, p = 0.02), and groin (68.5 vs. 87.8 vs. 94.7%, p < 0.0001). Increasing Hurley stage was associated with participants describing severe disease (1.8 vs. 35.4 vs. 55.3%, p < 0.0001) or very severe disease (1.8 vs. 2.7 vs. 26.3%, p < 0.0001). As expected, the more severe the HS was, the higher the mean DLQI score (8.8 vs. 13.4 vs. 17.8%, p < 0.0001) was. We found no significant association between Hurley stage and topical or oral antibiotics use.

Table 4.

Univariate analysis of factors associated with Hurley stage

 Univariate analysis of factors associated with Hurley stage
 Univariate analysis of factors associated with Hurley stage

Review of the Literature and Comparison with Other Large Cohorts (Table 5)

We selected eight references (6,253 participants) that described the clinical characteristics of HS patients [14, 18, 30‒35]. Patients mainly came from hospitals, and data were collected by questionnaire, medical examination, or from a health service database. The imbalance in sex ratio in our cohort (85.6% female) was previously identified and varied from 61.6 to 89.9% in the literature. The mean age at diagnosis in our study was 38 years, which is also consistent with previously published studies (30.4–53.7 years). Our study showed a long diagnosis delay of 9.3 years, similar to reports from the literature. Other sociodemographic characteristics (obesity, tobacco use, Caucasian phototype) were similar to those in other studies using a classical cohort approach. Locations of HS were similar among studies, with the dominant involvement of the front of the body in women and the back of the body in men. Compared with previously published studies, our cohort exhibited more severely affected disease, with Hurley stage III at 20.3% (compared to 3.4–11%). Of the female participants, 159 (46.9%) had never been pregnant, and 50 (14.8%) and 44 (13%) declared disease stability or improvement during pregnancy, respectively, as seen in the Kromann et al. [14] cohort.

Table 5.

Clinical characteristics of the study population compared with other published cohorts

 Clinical characteristics of the study population compared with other published cohorts
 Clinical characteristics of the study population compared with other published cohorts

In our cohort, the frequency of diabetes (2.8%) and arterial hypertension (3.8%) was not greater than that recorded in the French general population, unlike in previously published data (6.8–17.8% for diabetes and 14.2–48.9% for arterial hypertension). The number of 26 (6.6%) participants with depression is low compared with other studies.

Inflammatory bowel diseases and spondylarthritis were declared by 19 (4.8%) and 15 (3.8%) participants, respectively, and according to previously published data, the prevalence exceeded that in the general population.

This study highlights a predominance of females, smokers, and obese individuals among people with HS, all demographic features that are well known [36]. However, the proportion of women is high compared to others classic HS cohorts, which is predictable as women are more prone to enroll in epidemiological studies and respond to surveys [37]. Previous studies have shown a mean time from symptom onset to first contact with a physician of 7.2 (8.7) years [4]. Our study showed a delay to diagnosis of 9.2 years, which could be due to misdiagnosis of HS by nondermatologists, possibly contributing to a delay in diagnosis [38]. In comparison to men, women had a significantly lower delay in diagnosis and were younger. This is perhaps due to women being more concerned about their health and being willing to consult medical professionals quicker [39]. We may be underestimating the family history of HS as 95 (24%) participants did not know about their family history. Concerning education level, 29.3% of the participants had a university degree or higher, which is above the rate in previous studies [40]. Internet users may present better financial conditions and education.

Overall, 58.1% of participants were hospitalized because of HS, which reflects the severity of HS in this series [41]. Many treatments were reported; most were prescribed antibiotics, as recommended by many teaching societies [42, 43]. In fact, current management typically follows a stepwise approach depending on disease severity, starting with topical treatment for mild disease, prolonged courses of oral antibiotics for moderate-to-severe disease, and systemic biotherapies or surgery for more severe disease. Two-thirds of participants reported surgical intervention, which is consistent with other studies [44, 45]. Surgery is a highly effective modality for refractory HS associated with significantly improved quality of life [46, 47]. Only a few participants (9.6%) reported use of biologics, whereas >20% presented severe disease, which likely reflects restrictions in access to adalimumab due to the lack of reimbursement at the population level in France [48]. Treatment with apremilast was included within the “other medical treatment” category; however, recent data suggest that it could be an effective treatment for HS [49, 50].

The present survey also supports the idea that clinical presentation differs by sex. The front part of the body (i.e., pubis and groin) was predominant in women, whereas men were more affected on the back of the body (i.e., dorsal and neck area), which is consistent with published data [30].

We measured severity using the Hurley stage. In contrast to most previous reports [51], we found a low proportion of “benign” involvement in our series: only 13.6% of participants had Hurley stage I, whereas 20.3% had Hurley stage III. This low proportion of Hurley stage I may be explained by HS participants who register on ComPaRe being most concerned by their disease because they are more severely affected. It could be also an incorrect evaluation of Hurley stage self-assessment by participants, although several studies showed an interrater reliability of 76% between patients and physicians in the assessment of Hurley stage using photographs [52, 53].

In parallel, we noted an important impairment in quality of life (mean DLQI score 13.7). Overweight, obesity, and some HS localizations (genital, pubis, groin, and gluteal fold) were strongly associated with increasing disease stage, as assessed in previous studies [13, 14, 30]. However, smoking status was not associated with HS severity.

In our cohort, the frequency of diabetes (2.8%) and arterial hypertension (3.8%) was not greater than that recorded in the French general population, unlike in previously published data [17, 35]. Overall, 6.6% of participants declared having depression, which is low compared with other studies [54]. Inflammatory bowel disease was declared by 4.8% of participants and spondylarthritis by 3.8%, which is similar to the data of Richette et al. [55] (prevalence 3.7%), and the prevalence exceeded that in the general population.

Our study presents several strengths. Most of the HS patients were rather young and educated in the digital age, so they could be motivated for and were at ease with the Internet survey. This first French HS e-cohort could be considered a multicentric study. In fact, registered participants in ComPaRe were enrolled by hospitals or ambulatory care, which reduced selection bias and resulted in a wide variety of participants. Most sociodemographic and clinical data as well as factors associated with increasing severity support the literature. Thus, a self-reported survey without any medical control procedure is reliable and could be used for epidemiological studies and to evaluate therapeutics in “real-life” interventions.

Several limitations should be noted. Self-reported surveys are susceptible to a loss of information accuracy, recall bias, and an inability to confirm data authenticity. An assessment bias, particularly for Hurley stage, was possible because this score is usually assessed by physicians. Participants were guided by photos and definition capsules for this self-assessment, but there is a trend for patients to score their disease higher than the physician [52]. Also, patients could misunderstand the differences between “point assessment of Hurley stage,” which is asked in the questionnaire, and “worst Hurley stage ever.” There were some missing data, perhaps because of a misunderstanding of some questions. Nowadays there is no validated tool for severity self-assessment, and training might optimize the accuracy of the patients’ scoring results. Hurley stage is limited by its static character to evaluate the effectiveness of a new therapy. Dynamic scores as such as the HiSCR [56] or the modified Sartorius score [57] do not seem to be feasible for patients because of their complexity level. To assess the effectiveness of a new therapy, follow-up questionnaires can be done with questions about quality of life, reduction of flare-up, hospitalizations, and analgesic use.

However, e-epidemiology is having a revolutionary impact on how we monitor global health outcomes and behavior [58], and e-cohorts have many advantages, including reduced costs and administrative burden. In addition, the increased rate of identification of heterogeneous patients allows for better extrapolation of results. Self-administered questionnaires are frequently used to collect data related to a specific disease. Thus, their quality must be at least equivalent to those collected more traditionally by public health agencies through health staff in hospitals and doctors’ offices. Despite some discrepancies, e-cohorts represent the future of collection of clinic-epidemiological information or even recruitment of patients for clinical trials or pathophysiology studies. Training in self-assessment of disease severity should probably be optimized.

This is the first e-cohort of French individuals with HS whose observed clinical features and associations are mostly consistent with the literature. Recruitment of participants by such a web platform can be a faster way to get relevant scientific data for a wide variety of patients that could be used for epidemiological studies and to evaluate therapeutics in “real-life” interventions.

E-cohort data can be used for epidemiological studies and to evaluate therapeutics in “real-life” interventions.

We thank Laura Smales (BioMedEditing) for providing writing assistance in English.

All studies in the pooled analyses were conducted in accordance with the Declaration of Helsinki and the International Conference on Harmonization Good Clinical Practice Guidelines.

C. Hotz is an investigator for Novartis. P. Ravaud and V.-T. Tran are co-investigators of ComPaRe. P. Guillem is a consultant for advisory board meetings for AbbVie and received fees as speaker for AbbVie, Convatech, and Cicaplus. A.P. Villani received fees for participation on advisory boards from Bailleul and Merck. H. Bachelez is paid consulting activities for AbbVie, Almirall, BIOCAD, Boehringer-Ingelheim, Celgene, Janssen, Kyowa-Kirin, LEO Pharma, Lilly, Mylan, Novartis and UCB, and grant support from Boehringer-Ingelheim, Janssen, LEO Pharma, Novartis, and Pfizer. P. Wolkenstein is a consultant for Astra Zeneca. M.-A. Richard is an investigator for Novartis and UCB and a consultant for Novartis and AbbVie. M. Beylot-Barry has paid activities as a consultant, advisor, or speaker for AbbVie, Amgan, Celgene, Janssen LEO Pharma, Lilly, MSD, Novartis, and Pfizer. L. Penso, P. Perrot, M.-F. Bru, E. Jacquet, A. Nassif, M. Viguier, E. Sbidian, and M. Condamina have no conflict of interest.

ComPaRe was funded by the Assistance Publique Hôpitaux de Paris (AP-HP) and the Université de Paris.

M. Condamina wrote the initial draft of the article, to which all authors contributed. E. Sbidian supervised the word and critically revised the manuscript for important intellectual content. All authors have given final approval for the final version to be published.

1.
Jemec
GB
.
Clinical practice. Hidradenitis suppurativa
.
N Engl J Med
.
2012
Jan
;
366
(
2
):
158
64
.
[PubMed]
0028-4793
2.
Revuz
JE
,
Canoui-Poitrine
F
,
Wolkenstein
P
,
Viallette
C
,
Gabison
G
,
Pouget
F
, et al
.
Prevalence and factors associated with hidradenitis suppurativa: results from two case-control studies
.
J Am Acad Dermatol
.
2008
Oct
;
59
(
4
):
596
601
.
[PubMed]
0190-9622
3.
Ingram
JR
,
Abbott
R
,
Ghazavi
M
,
Alexandroff
AB
,
McPhee
M
,
Burton
T
, et al
.
The Hidradenitis Suppurativa Priority Setting Partnership
.
Br J Dermatol
.
2014
Dec
;
171
(
6
):
1422
7
.
[PubMed]
0007-0963
4.
Saunte
DM
,
Boer
J
,
Stratigos
A
,
Szepietowski
JC
,
Hamzavi
I
,
Kim
KH
, et al
.
Diagnostic delay in hidradenitis suppurativa is a global problem
.
Br J Dermatol
.
2015
Dec
;
173
(
6
):
1546
9
.
[PubMed]
0007-0963
5.
Pink
AE
,
Simpson
MA
,
Desai
N
,
Trembath
RC
,
Barker
JN
.
γ-Secretase mutations in hidradenitis suppurativa: new insights into disease pathogenesis
.
J Invest Dermatol
.
2013
Mar
;
133
(
3
):
601
7
.
[PubMed]
0022-202X
6.
Ingram
JR
.
The Genetics of Hidradenitis Suppurativa
.
Dermatol Clin
.
2016
Jan
;
34
(
1
):
23
8
.
[PubMed]
0733-8635
7.
Harrison
BJ
,
Read
GF
,
Hughes
LE
.
Endocrine basis for the clinical presentation of hidradenitis suppurativa
.
Br J Surg
.
1988
Oct
;
75
(
10
):
972
5
.
[PubMed]
0007-1323
8.
Mortimer
PS
,
Dawber
RP
,
Gales
MA
,
Moore
RA
.
Mediation of hidradenitis suppurativa by androgens
.
Br Med J (Clin Res Ed)
.
1986
Jan
;
292
(
6515
):
245
8
.
[PubMed]
0267-0623
9.
Matusiak
Ł
,
Bieniek
A
,
Szepietowski
JC
.
Bacteriology of hidradenitis suppurativa - which antibiotics are the treatment of choice
.
Acta Derm Venereol
.
2014
Nov
;
94
(
6
):
699
702
.
[PubMed]
0001-5555
10.
Nazary
M
,
van der Zee
HH
,
Prens
EP
,
Folkerts
G
,
Boer
J
.
Pathogenesis and pharmacotherapy of Hidradenitis suppurativa
.
Eur J Pharmacol
.
2011
Dec
;
672
(
1-3
):
1
8
.
[PubMed]
0014-2999
11.
Hessam
S
,
Sand
M
,
Georgas
D
,
Anders
A
,
Bechara
FG
.
Microbial Profile and Antimicrobial Susceptibility of Bacteria Found in Inflammatory Hidradenitis Suppurativa Lesions
.
Skin Pharmacol Physiol
.
2016
;
29
(
3
):
161
7
.
[PubMed]
1660-5527
12.
Assan
F
,
Gottlieb
J
,
Tubach
F
,
Lebbah
S
,
Guigue
N
,
Hickman
G
, et al
.
Anti-Saccharomyces cerevisiae IgG and IgA antibodies are associated with systemic inflammation and advanced disease in hidradenitis suppurativa
.
J Allergy Clin Immunol
.
2020
Aug
;
146
(
2
):
452
455.e5
.
[PubMed]
0091-6749
13.
Kromann
CB
,
Ibler
KS
,
Kristiansen
VB
,
Jemec
GB
.
The influence of body weight on the prevalence and severity of hidradenitis suppurativa
.
Acta Derm Venereol
.
2014
Sep
;
94
(
5
):
553
7
.
[PubMed]
0001-5555
14.
Kromann
CB
,
Deckers
IE
,
Esmann
S
,
Boer
J
,
Prens
EP
,
Jemec
GB
.
Risk factors, clinical course and long-term prognosis in hidradenitis suppurativa: a cross-sectional study
.
Br J Dermatol
.
2014
Oct
;
171
(
4
):
819
24
.
[PubMed]
0007-0963
15.
Patel
ZS
,
Hoffman
LK
,
Buse
DC
,
Grinberg
AS
,
Afifi
L
,
Cohen
SR
, et al
.
Pain, Psychological Comorbidities, Disability, and Impaired Quality of Life in Hidradenitis Suppurativa [corrected]
.
Curr Pain Headache Rep
.
2017
Nov
;
21
(
12
):
49
.
[PubMed]
1531-3433
16.
Kohorst
JJ
,
Kimball
AB
,
Davis
MD
.
Systemic associations of hidradenitis suppurativa
.
J Am Acad Dermatol
.
2015
Nov
;
73
(
5
Suppl 1
):
S27
35
.
[PubMed]
0190-9622
17.
Gold
DA
,
Reeder
VJ
,
Mahan
MG
,
Hamzavi
IH
.
The prevalence of metabolic syndrome in patients with hidradenitis suppurativa
.
J Am Acad Dermatol
.
2014
Apr
;
70
(
4
):
699
703
.
[PubMed]
0190-9622
18.
van der Zee
HH
,
de Winter
K
,
van der Woude
CJ
,
Prens
EP
.
The prevalence of hidradenitis suppurativa in 1093 patients with inflammatory bowel disease
.
Br J Dermatol
.
2014
Sep
;
171
(
3
):
673
5
.
[PubMed]
0007-0963
19.
Schneider-Burrus
S
,
Witte-Haendel
E
,
Christou
D
,
Rigoni
B
,
Sabat
R
,
Diederichs
G
.
High Prevalence of Back Pain and Axial Spondyloarthropathy in Patients with Hidradenitis Suppurativa
.
Dermatology
.
2016
;
232
(
5
):
606
12
.
[PubMed]
1018-8665
20.
Zouboulis
CC
,
Bechara
FG
,
Dickinson-Blok
JL
,
Gulliver
W
,
Horváth
B
,
Hughes
R
, et al
.
Hidradenitis suppurativa/acne inversa: a practical framework for treatment optimization - systematic review and recommendations from the HS ALLIANCE working group
.
J Eur Acad Dermatol Venereol
.
2019
Jan
;
33
(
1
):
19
31
.
[PubMed]
0926-9959
21.
Alikhan
A
,
Sayed
C
,
Alavi
A
,
Alhusayen
R
,
Brassard
A
,
Burkhart
C
, et al
.
North American clinical management guidelines for hidradenitis suppurativa: A publication from the United States and Canadian Hidradenitis Suppurativa Foundations: Part I: Diagnosis, evaluation, and the use of complementary and procedural management
.
J Am Acad Dermatol
.
2019
Jul
;
81
(
1
):
76
90
.
[PubMed]
0190-9622
22.
Grimstad
Ø
,
Tzellos
T
,
Dufour
DN
,
Bremnes
Ø
,
Skoie
IM
,
Snekvik
I
, et al
.
Evaluation of medical and surgical treatments for hidradenitis suppurativa using real-life data from the Scandinavian registry (HISREG)
.
J Eur Acad Dermatol Venereol
.
2019
Jun
;
33
(
6
):
1164
71
.
[PubMed]
0926-9959
23.
Eysenbach
G
.
Infodemiology and infoveillance: framework for an emerging set of public health informatics methods to analyze search, communication and publication behavior on the Internet
.
J Med Internet Res
.
2009
Mar
;
11
(
1
):
e11
.
[PubMed]
1438-8871
24.
International Telecommunication Union
. (
2011
) Measuring the information society 2011. 157 p. Available: http://www.itu.int/net/pressoffice/backgrounders/general/pdf/5.pdf. Accessed 29 June 2012.
25.
Salathé
M
,
Bengtsson
L
,
Bodnar
TJ
,
Brewer
DD
,
Brownstein
JS
,
Buckee
C
, et al
.
Digital epidemiology
.
PLOS Comput Biol
.
2012
;
8
(
7
):
e1002616
.
[PubMed]
1553-734X
26.
Ekman
A
,
Dickman
PW
,
Klint
A
,
Weiderpass
E
,
Litton
JE
.
Feasibility of using web-based questionnaires in large population-based epidemiological studies
.
Eur J Epidemiol
.
2006
;
21
(
2
):
103
11
.
[PubMed]
0393-2990
27.
Hercberg
S
,
Castetbon
K
,
Czernichow
S
,
Malon
A
,
Mejean
C
,
Kesse
E
, et al
.
The Nutrinet-Santé Study: a web-based prospective study on the relationship between nutrition and health and determinants of dietary patterns and nutritional status
.
BMC Public Health
.
2010
May
;
10
(
1
):
242
.
[PubMed]
1471-2458
28.
Smith
AB
,
King
M
,
Butow
P
,
Olver
I
.
A comparison of data quality and practicality of online versus postal questionnaires in a sample of testicular cancer survivors
.
Psychooncology
.
2013
Jan
;
22
(
1
):
233
7
.
[PubMed]
1057-9249
29.
Finlay
AY
,
Khan
GK
.
Dermatology Life Quality Index (DLQI)—a simple practical measure for routine clinical use
.
Clin Exp Dermatol
.
1994
May
;
19
(
3
):
210
6
.
[PubMed]
0307-6938
30.
Canoui-Poitrine
F
,
Revuz
JE
,
Wolkenstein
P
,
Viallette
C
,
Gabison
G
,
Pouget
F
, et al
.
Clinical characteristics of a series of 302 French patients with hidradenitis suppurativa, with an analysis of factors associated with disease severity
.
J Am Acad Dermatol
.
2009
Jul
;
61
(
1
):
51
7
.
[PubMed]
0190-9622
31.
Shalom
G
,
Freud
T
,
Harman-Boehm
I
,
Polishchuk
I
,
Cohen
AD
.
Hidradenitis suppurativa and metabolic syndrome: a comparative cross-sectional study of 3207 patients
.
Br J Dermatol
.
2015
Aug
;
173
(
2
):
464
70
.
[PubMed]
0007-0963
32.
Schrader
AM
,
Deckers
IE
,
van der Zee
HH
,
Boer
J
,
Prens
EP
.
Hidradenitis suppurativa: a retrospective study of 846 Dutch patients to identify factors associated with disease severity
.
J Am Acad Dermatol
.
2014
Sep
;
71
(
3
):
460
7
.
[PubMed]
0190-9622
33.
Vinding
GR
,
Miller
IM
,
Zarchi
K
,
Ibler
KS
,
Ellervik
C
,
Jemec
GB
.
The prevalence of inverse recurrent suppuration: a population-based study of possible hidradenitis suppurativa
.
Br J Dermatol
.
2014
Apr
;
170
(
4
):
884
9
.
[PubMed]
0007-0963
34.
Vazquez
BG
,
Alikhan
A
,
Weaver
AL
,
Wetter
DA
,
Davis
MD
.
Incidence of hidradenitis suppurativa and associated factors: a population-based study of Olmsted County, Minnesota
.
J Invest Dermatol
.
2013
Jan
;
133
(
1
):
97
103
.
[PubMed]
0022-202X
35.
Miller
IM
,
Ellervik
C
,
Vinding
GR
,
Zarchi
K
,
Ibler
KS
,
Knudsen
KM
, et al
.
Association of metabolic syndrome and hidradenitis suppurativa
.
JAMA Dermatol
.
2014
Dec
;
150
(
12
):
1273
80
.
[PubMed]
2168-6068
36.
Alikhan
A
,
Lynch
PJ
,
Eisen
DB
.
Hidradenitis suppurativa: a comprehensive review
.
J Am Acad Dermatol
.
2009
Apr
;
60
(
4
):
539
61
.
[PubMed]
0190-9622
37.
Kesse-Guyot
E
,
Assman
K
,
Andreeva
V
,
Castetbon
K
,
Méjean
C
, et al
.
Lessons Learned From Methodological Validation Research in E-Epidemiology
.
JMIR Public Health Surveill
.
2016
Oct
;
2
(
2
):
e160
. 2369-2960
38.
Loget
J
,
Saint-Martin
C
,
Guillem
P
,
Kanagaratnam
L
,
Becherel
PA
,
Nassif
A
, et al;
sous l’égide de « ResoVerneil »
.
[Misdiagnosis of hidradenitis suppurativa continues to be a major issue. The R-ENS Verneuil study]
.
Ann Dermatol Venereol
.
2018
May
;
145
(
5
):
331
8
.
[PubMed]
0151-9638
39.
Clerc
H
,
Tavernier
E
,
Giraudeau
B
,
Bourdais-Sallot
A
,
Samimi
M
,
Abdo
I
, et al
.
Understanding the long diagnostic delay for hidradenitis suppurativa: a national survey among French general practitioners
.
Eur J Dermatol
.
2019
Feb
;
29
(
1
):
97
9
.
[PubMed]
1952-4013
40.
Deckers
IE
,
Janse
IC
,
van der Zee
HH
,
Nijsten
T
,
Boer
J
,
Horváth
B
, et al
.
Hidradenitis suppurativa (HS) is associated with low socioeconomic status (SES): A cross-sectional reference study
.
J Am Acad Dermatol
.
2016
Oct
;
75
(
4
):
755
759.e1
.
[PubMed]
0190-9622
41.
Santos
JV
,
Lisboa
C
,
Lanna
C
,
Costa-Pereira
A
,
Freitas
A
.
Hospitalisations with Hidradenitis Suppurativa: An Increasing Problem That Deserves Closer Attention
.
Dermatology
.
2016
;
232
(
5
):
613
8
.
[PubMed]
1018-8665
42.
Zouboulis
CC
,
Desai
N
,
Emtestam
L
,
Hunger
RE
,
Ioannides
D
,
Juhász
I
, et al
.
European S1 guideline for the treatment of hidradenitis suppurativa/acne inversa
.
J Eur Acad Dermatol Venereol
.
2015
Apr
;
29
(
4
):
619
44
.
[PubMed]
0926-9959
43.
Alikhan
A
,
Sayed
C
,
Alavi
A
,
Alhusayen
R
,
Brassard
A
,
Burkhart
C
, et al
.
North American clinical management guidelines for hidradenitis suppurativa: A publication from the United States and Canadian Hidradenitis Suppurativa Foundations: Part II: Topical, intralesional, and systemic medical management
.
J Am Acad Dermatol
.
2019
Jul
;
81
(
1
):
91
101
.
[PubMed]
0190-9622
44.
Seyed Jafari
SM
,
Knüsel
E
,
Cazzaniga
S
,
Hunger
RE
.
A Retrospective Cohort Study on Patients with Hidradenitis Suppurativa
.
Dermatology
.
2018
;
234
(
1-2
):
71
8
.
[PubMed]
1018-8665
45.
Shlyankevich
J
,
Chen
AJ
,
Kim
GE
,
Kimball
AB
.
Hidradenitis suppurativa is a systemic disease with substantial comorbidity burden: a chart-verified case-control analysis
.
J Am Acad Dermatol
.
2014
Dec
;
71
(
6
):
1144
50
.
[PubMed]
0190-9622
46.
Fertitta
L
,
Hotz
C
,
Wolkenstein
P
,
Méningaud
JP
,
Sawan
D
,
Hersant
B
, et al
.
Efficacy and satisfaction of surgical treatment for hidradenitis suppurativa
.
J Eur Acad Dermatol Venereol
.
2020
Apr
;
34
(
4
):
839
45
.
[PubMed]
0926-9959
47.
Prens
LM
,
Huizinga
J
,
Janse
IC
,
Horváth
B
.
Surgical outcomes and the impact of major surgery on quality of life, activity impairment and sexual health in hidradenitis suppurativa patients: a prospective single centre study
.
J Eur Acad Dermatol Venereol
.
2019
Oct
;
33
(
10
):
1941
6
.
[PubMed]
0926-9959
48.
HUMIRA
. (adalimumab), antiTNFα [Internet]. Haute Autorité de Santé. [cited 2020 Apr 26]. Available from: https://www.has-sante.fr/jcms/c_2619541/fr/humira-adalimumab-antitnf
49.
Kerdel
FR
,
Azevedo
FA
,
Kerdel Don
C
,
Don
FA
,
Fabbrocini
G
,
Kerdel
FA
.
Apremilast for the Treatment of Mild-to-Moderate Hidradenitis Suppurativa in a Prospective, Open-Label, Phase 2 Study
.
J Drugs Dermatol
.
2019
Feb
;
18
(
2
):
170
6
.
[PubMed]
1545-9616
50.
Vossen
AR
,
van Doorn
MB
,
van der Zee
HH
,
Prens
EP
.
Apremilast for moderate hidradenitis suppurativa: results of a randomized controlled trial
.
J Am Acad Dermatol
.
2019
Jan
;
80
(
1
):
80
8
.
[PubMed]
0190-9622
51.
Canoui-Poitrine
F
,
Le Thuaut
A
,
Revuz
JE
,
Viallette
C
,
Gabison
G
,
Poli
F
, et al
.
Identification of three hidradenitis suppurativa phenotypes: latent class analysis of a cross-sectional study
.
J Invest Dermatol
.
2013
Jun
;
133
(
6
):
1506
11
.
[PubMed]
0022-202X
52.
Deckers
IE
,
Mihajlović
D
,
Prens
EP
,
Boer
J
.
Hidradenitis suppurativa: a pilot study to determine the capability of patients to self-assess their Hurley stage
.
Br J Dermatol
.
2015
;
172
(
5
):
1418
9
.
[PubMed]
0007-0963
53.
Rondags
A
,
Volkering
RJ
,
Turcan
I
,
Zuidema
YS
,
Janse
IC
,
Horvath
B
.
The Refined Hurley Patient Questionnaire: An Accurate Self-assessment Instrument for Deriving the Correct Refined Hurley Stage in Hidradenitis Suppurativa
.
Acta Derm Venereol
.
2019
Jun
;
99
(
7
):
703
4
.
[PubMed]
0001-5555
54.
Jalenques
I
,
Ciortianu
L
,
Pereira
B
,
D’Incan
M
,
Lauron
S
,
Rondepierre
F
.
The prevalence and odds of anxiety and depression in children and adults with hidradenitis suppurativa: systematic review and meta-analysis
.
J Am Acad Dermatol
.
2020
Aug
;
83
(
2
):
542
53
.
[PubMed]
0190-9622
55.
Richette
P
,
Molto
A
,
Viguier
M
,
Dawidowicz
K
,
Hayem
G
,
Nassif
A
, et al
.
Hidradenitis suppurativa associated with spondyloarthritis— results from a multicenter national prospective study
.
J Rheumatol
.
2014
Mar
;
41
(
3
):
490
4
.
[PubMed]
0315-162X
56.
Kimball
AB
,
Jemec
GB
,
Yang
M
,
Kageleiry
A
,
Signorovitch
JE
,
Okun
MM
, et al
.
Assessing the validity, responsiveness and meaningfulness of the Hidradenitis Suppurativa Clinical Response (HiSCR) as the clinical endpoint for hidradenitis suppurativa treatment
.
Br J Dermatol
.
2014
Dec
;
171
(
6
):
1434
42
.
[PubMed]
0007-0963
57.
Sartorius
K
,
Emtestam
L
,
Jemec
GB
,
Lapins
J
.
Objective scoring of hidradenitis suppurativa reflecting the role of tobacco smoking and obesity
.
Br J Dermatol
.
2009
Oct
;
161
(
4
):
831
9
.
[PubMed]
0007-0963
58.
Hessam
S
,
Salem
J
,
Bechara
FG
,
Haferkamp
A
,
Heidenreich
A
,
Paffenholz
P
, et al
.
Hidradenitis suppurativa gains increasing interest on World Wide Web: a source for patient information
.
Int J Dermatol
.
2017
Jul
;
56
(
7
):
726
32
.
[PubMed]
0011-9059