Does Alexithymia Affect Patients with Hidradenitis Suppurativa?

Abstract

Introduction

Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease associated with substantial psychosocial burden. Alexithymia, characterized by difficulties in identifying and expressing emotions, has been increasingly recognized in chronic disorders. However, data in HS remain limited. This study aimed to assess the prevalence of alexithymia in HS and its relationship with clinical and psychosocial parameters.

Material and Methods

This cross-sectional study included 123 consecutive adult HS patients. Disease severity was assessed using Hurley staging and the International Hidradenitis Suppurativa Severity Score System (IHS4). Alexithymia was evaluated with the Toronto Alexithymia Scale (TAS-20). Pain and pruritus were measured using the Numeric Rating Scale. Psychological burden was assessed with Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Hospital Anxiety and Depression Scale (HADS), illness acceptance was studied with Acceptance Illness Scale (AIS), while quality of life (QoL) was evaluated using Dermatology Life Quality Index (DLQI) and Hidradenitis Suppurativa Quality of Life (HiSQoL) questionnaire.

Results

Alexithymia was identified in 13.8% of patients, while 22.0% presented intermediate levels. The mean TAS-20 score was 46.45 ± 12.75 points. Females showed higher difficulty in identifying feelings (p=0.025). No significant associations were found between total alexithymia scores and disease severity. However, the externally oriented thinking (EOT) domain was significantly higher in more severe disease. TAS-20 scores showed weak correlations with IHS4, pain, and pruritus. Stronger associations were observed with depressive symptoms, anxiety, impaired QoL, and poorer disease acceptance, particularly for the difficulty in identifying feelings domain.

Conclusion

Alexithymic traits affect a substantial proportion of HS patients and are primarily associated with psychosocial burden rather than objective disease severity. Assessment of alexithymia, especially its domains, may provide clinically relevant insights and support a more comprehensive, multidisciplinary approach to HS management.

Introduction

Hidradenitis suppurativa (HS) is a chronic, inflammatory, and recurrent disease of the pilosebaceous unit that primarily affects intertriginous areas, including the axillae, groin, gluteal, and anogenital regions. It is characterized by painful nodules, abscesses, sinus tract formation, and scarring, frequently leading to substantial physical discomfort, functional impairment, and long-term disability.^1–3 The epidemiology of HS demonstrates considerable geographic variability depending on the studied population and diagnostic methodology. In Europe, prevalence estimates around 1.0%, in the United States, HS prevalence seems to be higher, while in Asian countries reported prevalence ranges from 0.14% to 0.19%. Moreover, important sex-related differences have been described. In most European and North American populations, HS predominantly affects females, with reported female-to-male ratios ranging from approximately 2–3:1, whereas in some East Asian populations males appear to be more frequently affected. HS most commonly develops in young adults, with disease onset typically occurring between 18 and 30 years of age.¹ It is generally accepted that the disease remains underrecognized and is often associated with significant diagnostic delay, contributing to disease progression and cumulative burden.^4,5

The pathogenesis of HS is complex and multifactorial, involving genetic predisposition, dysregulated immune responses, and environmental factors. Importantly, HS is increasingly recognized as a systemic inflammatory condition associated with multiple comorbidities, including metabolic syndrome, cardiovascular disease, inflammatory bowel disease, and spondyloarthropathies.^1,6 However, beyond its somatic manifestations, HS imposes a profound psychosocial burden that markedly affects patients’ quality of life (QoL), often exceeding that observed in other dermatological disorders.⁷

Patients with HS frequently experience intense pain, pruritus, malodor, and drainage, as well as lesions located in intimate body areas, which significantly impair social functioning, interpersonal relationships, and sexual health.^1,8 These factors contribute to stigmatization, social withdrawal, and reduced occupational productivity. Consequently, psychiatric comorbidities are highly prevalent in this population, with depression and anxiety reported in a substantial proportion of patients.^9,10 Notably, previous studies have demonstrated that over 20% of individuals with HS exhibit clinically relevant depressive and anxiety symptoms, which are strongly associated with disease severity, subjective symptom burden, and impaired QoL.⁹ Beyond conventional psychiatric comorbidities such as depression and anxiety, increasing attention has recently been directed toward disturbances in higher-order emotional processing in patients with chronic inflammatory diseases. Difficulties in recognizing, interpreting, and expressing emotions may contribute to maladaptive coping strategies, impaired interpersonal functioning, and reduced psychological adaptation to chronic illness.¹¹

Alexithymia, a multidimensional psychological construct first described by Sifneos, refers to difficulties in identifying, distinguishing, and describing emotions, as well as a tendency toward externally oriented thinking and limited imaginative processes. Individuals with alexithymia often exhibit impaired emotional awareness and communication, which may negatively influence interpersonal functioning and the doctor-patient relationship.¹¹ Importantly, alexithymia may represent more than a simple coexisting psychological feature. It may potentially act as a vulnerability or mediating factor linking chronic disease burden with adverse psychosocial outcomes. The prevalence of alexithymia in the general population is estimated at approximately 10%, but it appears to be considerably higher in patients with chronic medical disorders, including also dermatological conditions.^11,12 Previous studies in dermatology have demonstrated increased prevalence of alexithymia in several chronic inflammatory and visible skin diseases, including psoriasis, atopic dermatitis, vitiligo, and acne. Moreover, alexithymia has been associated with impaired QoL, stigmatization, and higher levels of anxiety and depressive symptoms in dermatological patients.¹² Despite growing recognition of the psychosocial burden of HS, the role of higher-order emotional processing disturbances, such as alexithymia, remains insufficiently understood.

Although previous studies have evaluated alexithymia in patients with HS, available data remain relatively limited and focused mainly on prevalence estimates and selected psychological associations.¹² In particular, there is a lack of comprehensive studies simultaneously evaluating alexithymia in the context of disease severity, subjective symptom burden, and broader psychological comorbidities. Therefore, further investigation of alexithymia in HS appears clinically relevant.

Materials and Methods

Study Design and Participants

This cross-sectional observational study was conducted between June 2025 and January 2026 among consecutive adult patients diagnosed with HS. Participants were recruited during routine dermatological consultations at tertiary referral centers in Wroclaw and Cracow, Poland. Inclusion criteria comprised age ≥18 years and a confirmed diagnosis of HS established by experienced dermatologists. Exclusion criteria included previously diagnosed psychiatric disorders, current psychiatric treatment or psychotherapy, cognitive impairment preventing reliable questionnaire completion, and inability to independently complete the self-reported assessments. A total of 132 patients presenting during the study period were considered for inclusion, of whom 123 completed all required assessments and were included in the final analysis (response rate: 93.2%). All participants provided written informed consent prior to enrollment. Demographic and clinical data, including age, sex, and disease duration, were collected for all participants. The characteristics of the study group is grouped in Table 1.

Table 1.

Clinical Characteristics of the Study Population

Variable	Total	Females	Males	p-value
Number of patients, n (%)	123	62 (50.4%)	61 (49.6%)
Age (years), mean ± SD	36.35 ± 12.37	36.27 ± 12.95	36.43 ± 11.87	NS
Disease duration (years), mean ± SD	9.86 ± 6.45	10.01 ± 7.22	9.71 ± 5.63	NS
Hurley stage, n (%)				0.003
Stage I	19 (15.4)	11 (17.7)	8 (13.1)
Stage II	86 (69.9)	49 (79.0)	37 (60.7)
Stage III	18 (14.7)	2 (3.3)	16 (26.2)
IHS4, mean ± SD	8.51 ± 6.99	7.49 ± 6.55	9.62 ± 7.36	NS
IHS4 categories, n (%)				NS
IHS-4≤3 points, mild	35 (28.4%)	23 (37.1%)	12 (19.7%)
IHS-4 4–10 points, moderate	43 (35.0%)	22 (35.5%)	21 (34.4%)
IHS-4 >10 points, severe	45 (36.6%)	17 (27.4%)	28 (45.9%)
Pruritus (NRS points), mean ± SD	5.7 ± 2.2	5.9 ± 2.3	5.5 ± 2.1	NS
Pain (NRS points), mean ± SD	7.3 ± 2.1	7.8 ± 2.1	6.8 ± 2.1	NS

Abbreviations: N, number; SD, standard deviation; IHS-4, International Hidradenitis Suppurativa Severity Score System; NRS, Numeral Rating Scale; NS, non-significant.

The study was conducted in accordance with the Declaration of Helsinki and approved by the local ethics committee (Lower Silesian Medical Chamber, Wroclaw, Poland; decision no. 12/BNBP/2025).

Clinical Assessment of HS

Clinical assessment was performed by experienced dermatologists with expertise in HS management and the application of validated HS severity instruments, including Hurley staging and IHS4 scoring. The Hurley staging system was applied to classify patients into three stages based on lesion extent, sinus tract formation, and scarring.¹³ Additionally, the International Hidradenitis Suppurativa Severity Score System (IHS4) was used as a dynamic measure of disease activity, calculated as: number of nodules ×1 + number of abscesses ×2 + number of draining tunnels ×4. Based on the total score, HS severity was categorized as mild (≤3), moderate (4–10), or severe (>10).¹⁴

Subjective symptoms, including pain and pruritus, were assessed using the Numeric Rating Scale (NRS). Patients rated symptom intensity on a scale from 0 (no symptoms) to 10 (worst imaginable symptoms), referring both to the most severe symptoms during the previous three days.^15,16

Assessment of Alexithymia

Alexithymia was evaluated using the Toronto Alexithymia Scale (TAS-20), a validated 20-item self-reported questionnaire rated on a 5-point Likert scale. The total score ranges from 20 to 100 points, with higher scores indicating greater alexithymic traits. The scale comprises three subdomains: difficulty identifying feelings (DIF), difficulty describing feelings (DDF), and externally oriented thinking (EOT). Based on established cut-offs, scores ≥61 points indicate alexithymia, 52–60 points possible alexithymia (intermediate alexithymia), and ≤51 points absence of alexithymia.¹⁷

Assessment of QoL

QoL was assessed using two validated instruments. The Dermatology Life Quality Index (DLQI) is a 10-item questionnaire evaluating the impact of skin disease on daily functioning over the previous week, with total scores ranging from 0 to 30 points. Higher scores indicate greater impairment.¹⁸ Additionally, the Hidradenitis Suppurativa Quality of Life (HiSQoL) questionnaire, a 17-item disease-specific instrument, was used to assess the physical, emotional, and social burden of HS. Similarly to DLQI higher scores correspond to more impaired QoL.¹⁹

Assessment of Illness Acceptance

Illness acceptance was assessed using the Acceptance of Illness Scale (AIS), a validated self-reported instrument designed to evaluate psychological adaptation to chronic disease. The AIS consists of 8 statements describing the negative consequences of illness, including limitations in daily functioning, reduced independence, and lowered self-esteem. Each item is rated on a 5-point Likert scale ranging from 1 (“strongly agree”) to 5 (“strongly disagree”), yielding a total score between 8 and 40 points. Higher scores indicate better illness acceptance and more effective psychological adaptation, whereas lower scores reflect poor acceptance and greater emotional distress.^20,21

Assessment of Psychological Variables

Depressive symptoms were assessed using the Patient Health Questionnaire-9 (PHQ-9), with scores ≥10 indicating clinically relevant depressive symptoms.²² Anxiety symptoms were evaluated using the Generalized Anxiety Disorder-7 (GAD-7) scale, with scores ≥8 indicating clinically significant anxiety.²³ Additionally, anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS), including the HADS-A (anxiety) and HADS-D (depression) subscales.²⁴ The higher scores of all the above mentioned scales the higher expression of depressive/anxiety symptoms.

Statistical Analysis

Statistical analyses were performed using IBM SPSS Statistics version 26 (IBM Corp., Armonk, NY, USA). The normality of data distribution was assessed using the Shapiro–Wilk test. Continuous variables were presented as means ± standard deviations or medians with interquartile ranges, depending on distribution. Categorical variables were expressed as absolute numbers and percentages. Comparisons between two groups were performed using the Student’s t-test or the Mann–Whitney-U test. For comparisons involving more than two groups, one-way ANOVA or the Kruskal–Wallis test was used, followed by post hoc Bonferroni correction. Categorical variables were analyzed using the χ²-test or Fisher’s exact test. Correlation analyses were conducted using Pearson’s or Spearman’s coefficients, as appropriate. All tests were two-tailed, and a p-value <0.05 was considered statistically significant.

Results

Alexithymia was present in 17 (13.8%) individuals, while 27 (22.0%) were classified as having intermediate alexithymia. The majority of patients (n=79; 64.2%) did not exhibit alexithymia. When analyzed by sex, alexithymia was more frequently observed in females than in males (17.7% vs 9.8%), although this difference was not statistically significant. Intermediate alexithymia was found in 24.2% of females and 19.7% of males. In contrast, the absence of alexithymia was slightly more common among males compared to females (70.5% vs 58.1%) (Figure 1).

Figure 1.

Alexithymia in hidradenitis suppurativa patients.

The mean TAS-20 score in the whole study group was 46.45 ± 12.75 points. The mean scores for individual domains were 15.77 ± 6.62 points for DIF, 11.85 ± 4.13 points for DDF, and 18.83 ± 5.22 points for EOT. No significant differences were observed in the total TAS-20 score between females and males. However, females demonstrated significantly higher DIF scores compared to males (17.20 ± 6.88 points vs 14.32 ± 6.05 points; p=0.025). No significant differences between sexes were found for DDF or EOT domains (Table 2).

Table 2.

Alexithymia Scores in Gender and Disease Stage/Severity Hidradenitis Suppurativa Groups

Parameter	TAS-20	DIF	DDF	EOT
Whole group	46.45±12.75	15.77±6.62	11.85±4.13	18.83±5.22
Gender
Females	47.56±14.12	17.20±6.88*	12.05±4.34	18.31±5.51
Males	45.33±11.21	14.32±6.05	11.65±3.94	19.37±4.89
Hurley stage
Hurley I	45.57±10.77	16.86±5.3	11.64±3.5	17.07±5.36
Hurley II	44.62±13.03	14.88±6.87	11.36±4.17	18.38±5.12
Hurley III	51.0±10.23	16.75±6.0	12.67±4.09	21.58±3.5^
IHS4
Mild	42.03±12.45	14.45±5.91	11.10±4.38	16.48±4.86
Moderate	46.97±10.73	15.59±6.72	11.59±3.39	19.78±4.61
Severe	47.57±13.62	16.30±6.96	12.00±4.35	19.27±5.41$

Notes:*p=0,025; ^p=0.033, post-hoc analysis: Hurley II vs Hurley III – p=0.048; ^$p=0.022, post-hoc analysis: Hurley I vs Hurley II – p=0.028.

Abbreviations: TAS-20, Toronto Alexithymia Scale; DIF, Difficulty in Identifying Feelings; DDF, Difficulty in Describing Feelings; EOT, Externally Oriented Thinking; IHS4, International Hidradenitis Suppurativa Severity Score System.

With regard to disease staging assessed by Hurley scale, no statistically significant differences were found in total TAS-20 scores or DIF and DDF domains. However, a significant difference was observed for the EOT domain (p=0.033), with higher scores in patients with more advanced disease (Figure 2). Post-hoc analysis revealed a significant difference between Hurley stage II and III (p=0.048). Similarly, no significant differences were observed in total TAS-20, DIF, or DDF scores across IHS4 severity groups. In contrast, EOT scores differed significantly between groups (p=0.022), with post-hoc analysis indicating a significant difference between mild and moderate disease severity (p=0.028) (Table 2).

Figure 2.

Alexithymia and its domains according to Hurley staging. * - significant difference in EOT between Hurley stages.

Abbreviations: DIF, Difficulty in Identifying Feelings; DDF, Difficulty in Describing Feelings; EOT, Externally Oriented Thinking.

Correlation analysis revealed that alexithymia scores were significantly associated with multiple clinical and psychosocial parameters (Table 3). TAS-20 scores showed a significant, albeit weak, correlation with disease severity measured by IHS4. Weak but significant correlations were also found with pain and pruritus intensity. Higher TAS-20 scores were significantly correlated with greater depressive symptoms, as well as with anxiety severity assessment. In addition, alexithymia was significantly associated with poorer disease acceptance and impaired QoL. Analysis of alexithymia domains demonstrated that the DIF component showed the strongest associations with psychological variables, including PHQ-9, GAD-7, HADS-D, HADS-A and AIS. Similar but generally weaker correlations were observed for DDF. In contrast, the EOT domain showed fewer and weaker associations, with significant correlations observed mainly for QoL measures, AIS and HADS-D (Table 3).

Table 3.

Correlations Between Alexithymia and Clinical and Psychosocial Parameters

Parameter	TAS-20	DIF	DDF	EOT
Age	r=0.51 NS	r=0.039 NS	r=0.14 NS	r=0.274 p=0.003
Disease duration	r=0.19 NS	r=0.10 NS	r=0.00 NS	r=0.15 NS
IHS4	r=0.317 p=0.002	r=0.213 p=0.042	r=0.25 p=0.016	r=0.257 p=0.013
Pain intensity	r=0.256 p=0.030	r=0.225 NS	r=0.193 NS	r=0.179 NS
Pruritus intensity	r=0.254 p=0.041	r=0.209 NS	r=0.137 NS	r=0.22 NS
Quolity of life:
DLQI	r=0.486 p<0.001	r=0.394 p<0.001	r=0.449 p<0.001	r=0.383 p<0.001
HISQOL	r=0.518 p<0.001	r=0.453 p<0.001	r=0.451 p<0.001	r=0.366 p<0.001
AIS	r=−0.624 p<0.001	r=−0.617 p<0.001	r=−0.533 p<0.001	r=−0.344 p<0.001
Depression:
PHQ-9	r=0.601 p<0.001	r=0.667 p<0.001	r=0.457 p<0.001	r=0.257 p=0.004
HADS-D	r=0.595 p<0.001	r=0.597 p<0.001	r=0.428 p<0.001	r=0.370 p<0.001
Anxiety:
GAD-7	r=0.496 p<0.001	r=0.635 p<0.001	r=0.406 p<0.001	r=0.097 NS
HADS-A	r=0.486 p<0.001	r=0.559 p<0.001	r=0.401 p<0.001	r=0.171 NS

Abbreviations: TAS-20, Toronto Alexithymia Scale; DIF, Difficulty in Identifying Feelings; DDF, Difficulty in Describing Feelings; EOT, Externally Oriented Thinking; HIS-4, International Hidradenitis Suppurativa Severity Score System; DLQI, Dermatology Life Quality Index; HISQoL, Hidradenitis Suppurativa Quality of Life; AIS, Acceptance Illness Scale; PHQ-9, Patient Health Questionnaire-9; HADS-D, Hospital Anxiety and Depression Scale – Depression; GAD-7, Generalized Anxiety Disorder-7; HADS-A, Hospital Anxiety and Depression Scale – Anxiety; NS, non-significant.

Discussion

The present study provides further insight into the role of alexithymia in patients with HS, confirming that disturbances in emotional processing affect a substantial proportion of this population. Although the prevalence of definite alexithymia observed in our cohort was relatively moderate, the combined proportion of patients with definite and borderline (intermediate) alexithymia indicates that clinically relevant alexithymic traits are present in more than one-third of HS patients. These findings highlight the importance of considering alexithymia as a meaningful component of the multidimensional burden associated with HS.

Our results are partly consistent with previous HS studies, which reported higher prevalence rates of alexithymia ranging from approximately 44% to over 60%.^25–27 However, these discrepancies may be explained by methodological differences, including different questionnaires used, varying cut-off thresholds and the inclusion of intermediate alexithymia cases in earlier reports. Importantly, when considering both definite and intermediate alexithymia, our findings align more closely with previously published data, supporting the notion that emotional processing deficits are highly prevalent in HS.

From a broader dermatological perspective, our findings are in line with evidence demonstrating that alexithymia is more common in patients with chronic skin diseases compared with the general population. A systematic review by Holmes et al²⁸ showed that alexithymia is consistently elevated across multiple dermatoses, including psoriasis, atopic dermatitis, alopecia areata, vitiligo, and HS, and is closely linked to increased disease burden and psychosocial comorbidity. Similarly, a cross-sectional study reported that the prevalence of alexithymia across dermatological conditions ranges widely, reaching up to 71% in HS and remaining substantially higher than in healthy individuals.²⁹

Comparative data from specific diseases further support these observations. In psoriasis, a meta-analysis estimated the pooled prevalence of alexithymia at approximately 28%, which, although lower than some HS estimates, still indicates a significant psychological burden. Moreover, in psoriasis, alexithymia has been shown to play a mediating role between stigma and mental health outcomes, suggesting that impaired emotional processing may contribute to the development of anxiety and depressive symptoms.^30,31 These findings are particularly relevant in the context of HS, where stigmatization, visible lesions, and disease chronicity are similarly pronounced,^1,3 potentially amplifying the role of alexithymia in shaping psychological distress.

An additional finding of interest was the significantly higher DIF scores observed among female patients. To the best of our knowledge, sex-specific differences within individual alexithymia domains have not been extensively investigated in HS. Previous studies evaluating overall alexithymia levels in HS did not identify significant differences between men and women.^25–27 Nevertheless, it may be hypothesized that women with HS experience unique psychosocial challenges related to body image, self-esteem, interpersonal relationships, and stigmatization, which could influence certain aspects of emotional processing. Given the exploratory nature of this observation, further studies are required to determine whether sex-related differences in alexithymia domains represent a reproducible feature of HS populations.

Interestingly, in our study, total alexithymia scores were not strongly associated with objective measures of disease severity, which is consistent with some previous HS studies.²⁵ This suggests that alexithymia may not be directly driven by clinical severity but rather reflects an independent psychological dimension. However, a statistically significant association was observed between the externally oriented thinking (EOT) domain and more advanced disease severity. Given the relatively modest magnitude of this finding and the cross-sectional nature of the study, its clinical significance remains uncertain. Nevertheless, it may be hypothesized that prolonged exposure to chronic disease burden could influence certain aspects of emotional processing and cognitive coping styles, although this possibility requires further investigation in longitudinal studies.

More importantly, our results demonstrated moderate-to-strong associations between alexithymia and psychological variables, including depressive and anxiety symptoms, impaired QoL, and reduced illness acceptance. These relationships were particularly pronounced for the “difficulty identifying feelings” (DIF) domain, which showed the strongest correlations with psychological distress. This observation is in line with previous literature suggesting that DIF represents the most clinically relevant component of alexithymia, closely linked to affective dysregulation and vulnerability to psychiatric comorbidities.³²

The relationship between alexithymia and QoL deserves particular attention. Our findings confirm that higher levels of alexithymia are associated with significantly impaired QoL, which is consistent with data from other dermatological and chronic conditions.³² This association may be explained by several mechanisms. Patients with alexithymia may have difficulty recognizing and articulating emotional distress, leading to maladaptive coping strategies and reduced engagement in social interactions. Furthermore, alexithymia has been associated with poorer doctor–patient communication and lower treatment adherence, which may further exacerbate disease burden and negatively impact clinical outcomes.^33,34

An important and relatively novel finding of the present study was the association between alexithymia and lower illness acceptance. Psychological adaptation to chronic disease requires not only adjustment to physical symptoms and treatment demands, but also effective recognition, processing, and integration of emotional experiences related to the illness. Individuals with alexithymia may experience difficulties identifying and understanding their emotional responses to chronic disease, which could impair adaptive coping and acceptance processes.^11,12 Similar associations between alexithymic traits and poorer psychological adaptation have been reported in other chronic medical conditions, suggesting that impaired emotional awareness may represent an important barrier to successful adjustment to long-term illness.^35,36

Several limitations of the present study should be acknowledged. The cross-sectional design precludes causal inference, and the use of self-reported questionnaires may introduce reporting bias. Furthermore, the lack of a control group limits direct comparison with healthy individuals. Future longitudinal studies are needed to better understand the temporal relationship between alexithymia and disease course, as well as to evaluate the impact of targeted psychological interventions.

In conclusion, clinically significant alexithymia was identified in a subset of patients with hidradenitis suppurativa and was associated with greater psychological burden, poorer QoL, and lower illness acceptance. While the prevalence of alexithymia observed in our cohort was only moderately higher than estimates reported for the general population, the identified associations suggest that difficulties in emotional processing may represent a relevant psychosocial characteristic in some patients with HS.

Informed Consent

The written consent was obtained from all enrolled patients. The study was conducted in accordance with the Declaration of Helsinki and approved by the local ethics committee (Lower Silesian Medical Chamber, Wroclaw, Poland; decision no. 12/BNBP/2025).

Disclosure

Piotr Krajewski reports Honoraria from Novartis, UCB, Celltrion; Meeting/travel support from Celltrion, outside the submitted work. The authors declare that they have no other conflicts of interest to disclose.