Clinical Features of Persons Suffering from Acne Inversa

Acne inversa (AI)/hidradenitis suppurativa (HS) is an inflammatory disease that mainly appears in the axillary, inguinal, anogenital, and perianal areas. It affects approximately 1% of the population. There is currently an average delay to diagnosis of seven to nine years, as the disease manifestations are easily mistaken for those of single lesions (usually abscesses) (1).

In the EsmAiL project (evaluation of a structured, guideline-based multimodal treatment concept for patients with acne inversa), supported by the Innovation Fund of the German Federal Joint Committee, nine doctors’ practices, two hospitals, and three wound centers were designated as acne inversa centers (AIC). In an AiC, patients were treated according to a structured, interdisciplinary treatment plan, based on current guidelines and were also offered “LAight-therapy” (a combination of intense pulsed light and radiofrequency for the treatment of AI), patient education, pain management, and wound and lesion management. The aim of the EsmAiL project, led by the Department of Dermatology of Universitätsmedizin Mainz, is to evaluate whether a complex intervention, implemented by trained AIC, can slow the progression of the disease compared to standard care. In this article, we assess and present the baseline of the EsmAiL project.

Methods

The cross-sectional analysis includes the baseline data of the study population in EsmAiL. The study was approved by the relevant ethics committees and entered into the German Clinical Trials Registry (DRKS00022135). General practitioners and specialists from outside the AIC were trained in the clinical features of AI so that they could perform baseline and end-of-intervention assessment.

Patients were recruited across Germany from 29 September 2020 to 31 July 2021. Participation was open to adults with AI who had at least three inflammatory lesions at the time of inclusion, and whose dermatological quality of life index (DLQI) was above 5 points. The DLQI, a measure of quality-of-life impairment, ranges from 0 to 30. All participants were comprehensively informed about the study and gave written consent.

Disease activity was measured with the Hurley severity classification (2), the International Hidradenitis Suppurativa Severity Score System (IHS4) (3), and the Numeric Rating Scale for pain (4). Disease burden was measured with the DLQI and the Hospital Anxiety and Depression Scale (HADS), both of which are validated scores, and by the number of days of inability to work. The socioeconomic variables considered were the patients’ marital status, educational level, and occupational status. The body-mass index (BMI), smoking status, and accompanying illnesses (out of a list of common ones) were assessed as potential risk factors. The trained general practitioners and specialists documented the clinical findings on data entry forms. Demographic data and patient-reported outcomes (PRO) were obtained from the patients by questionnaire. They also filled out digital questionnaires about their illness history, days of inability to work, personal situation, and satisfaction with care.

In descriptive analyses, we report absolute and relative frequencies for discrete variables and mean values and associated standard deviations for continuous variables. The characteristics of the study sample were compared to those of the general German population (with age adjustment where appropriate) with the aid of data from the German Federal Statistical Office.

Results

Among the 726 screened patients, 553 met the criteria for inclusion; 72 were classified as Hurley grade I, 343 as Hurley grade II, and 138 as Hurley grade III. Most of them (78.3%) were women. Their mean age was 39.0 ± 10.47 years, which is lower than the mean age of the German population (table).

Table. Patient characteristics.

Endpoint (n = 553)	Mean ± SD Relative frequency	Comparison to general population
Demographic characteristics
Age (years)	39.0 ± 10.47	Ø 44.6*3
Sex Male Female	21.7% 78.3%	49.3% *4 50.7% *4
Medical risk factors
Smoking status Smoker Nonsmoker Former smoker	63.9% 18.6% 17.5%	30.1% *5 52.0%5 17.9*5
Cigarettes/day (n = 333)	14.3 ± 7.53	n. a.
Body mass index	32.2 ± 7.27	Ø 26.0*6
Accompanying diseases Hypertension Depression Type II Diabetes	1.6 ± 0.96 19.5% 27.5% 24.1%	11.8% *7 8.4% *8 7.2%9
Socioeconomic factors
Educational level (n = 508) Secondary school Vocational training Higher education*1	35.2% 40.0% 24.8%	33.5% *10 46.6%10 18.5% *10
Employment status Employed Unemployed*2	68.7% 31.3%	85.8%11 14.2%11
Days off work (n = 380)	16.4 ± 35.00	n. a.
Disease burden
Hurley Grade Hurley I Hurley II Hurley III	13.0% 62.0% 25.0%	n. a.
Pain (Numerical Rating Scale [NRS])	6.8 ± 2.16	n. a.
Dermatological Life Quality Index (DLQI)	17.8 ± 6.5	n. a.

*¹ college degree or equivalent

*² includes: jobless, student, inability to work in previous occupation, inability to work in any occupation, retired, other

*³, ⁴, ¹⁰, ¹¹ age-adjusted data for the general population from the Federal Statistical Office

*⁵, ⁶ age-adjusted data for the general population from the German federal health report agency (Gesundheitsberichterstattung des Bundes, GBE)

*⁷ DOI: 10.17886/RKI-GBE-2017–007

*⁸ DOI: 10.1007/s00103–013–1688–3

*⁹ DOI: 10.3238/arztebl.2016.0177

n. a; not applicable; SD, standard deviation

The mean inflammatory activity score (IHS4) was 18.2 ± 18.56, and the mean pain score was 6.8 ± 2.16. The mean DLQI and HADS scores were 17.8 ± 6.5 and 17.3 ± 7.82, respectively.

As for the socioeconomic factors that were evaluated (marital status, educational level, and occupational status), persons with AI were more likely to be unmarried than the general population and had a higher average educational level, but they were also more likely to be unemployed (table).

Among the AI patients, cigarette smoking and obesity (BMI ≥ 30) were both markedly more common than in similarly aged persons in the general population (table). They also had an above average prevalence of type 2 diabetes mellitus, depression, and hypertension (table). 47.8% of the respondents stated that they were dissatisfied with the care they had received for AI, and 30.8% said they were very dissatisfied.

Discussion

These findings confirm that AI is a burdensome disease that severely affects the sufferers’ ability to work and impairs their activities in everyday life. In relation to similarly aged persons from the general population, persons with AI more commonly suffer from type 2 diabetes mellitus, depression, obesity, and hypertension (table) and are thus at greater risk of cardiovascular sequelae and associated mortality (5).

Only one-fifth of the patients in the sample were satisfied with the care they had received, and only 1.9% were very satisfied. It is clear that the outpatient care of persons with AI is in need of improvement.

The findings may have been affected by selection bias, in that the participants learned of the study through various channels including doctors’ practices, self-help groups, and the Internet. They are therefore likely to have been better informed about their illness than the overall population of AI patients and to have been suffering from AI of greater than average severity.