Rook and Wilkinson (5) already argued in the late 1970s that “[.] the role of emotional factors on diseases of the skin is of such significance that, if they are ignored, the effective management of at least 40% of the patients attending departments of dermatology is impossible” (6). From an evolutionary standpoint, Kellett and Gilbert (7) center their focus on self-related negative emotions like shame and disgust. Their bio-psycho-social model, as depicted in Figure 1, serves as the foundation for this systematic review. They argue that acne’s development and progression stem from a combination of genetic factors and the stressors of puberty. The authors propose that when acne symptoms become prominent, individuals experience negative thoughts and emotions, especially related to the self, along with social challenges. These internal struggles and interpersonal issues adversely affect mood, behavior, and immune system function, further impacting stress levels, acne symptoms, and the emergence of additional psychological problems. The bio-psycho-social model of acne (Figure 1) can also be applied to the clinical presentation of psoriasis and atopic eczema, as all three conditions involve inflammatory skin issues that can negatively impact social life, emotional and psychological wellbeing. The connection of stress, social factors, and negative emotions with skin diseases is supported by evidence (6, 8), while a systematic review on shame and self-disgust in skin diseases is lacking.

The basic human emotion of disgust is described as a form of rejection that arises from the need to distance oneself from a contaminated stimulus and is characterized by feelings of nausea and revulsion (9). Disgust is considered to be an adaptive emotion, which is an evolved response to objects in the environment that pose a (perceived) threat in terms of contagion through infectious diseases (10). Self-disgust describes feelings of reluctance and repulsion directed against specific aspects of one’s own person (11), whereas (general) shame is believed to be an incapacitating emotion that is accompanied by the feeling of being small, inferior, and of “shrinking,” whereby the self, as a whole, is devalued and considered to be inadequate, incompetent, and worthless (12). Shame is viewed from a more differentiated perspective, and a distinction is made between external and internal shame. External shame refers to the experience of the self as existing negatively in the minds of others, and thus as having visible deficits, failures, or mistakes (13). Internal shame, by contrast, is linked to the inner dynamics of the self and one’s judgements and evaluations (13). The distinction between shame and embarrassment is debated, with researchers suggesting distinctions in terms of intensity of affect, severity of transgression or patterns of attribution to the presented (embarrassment) vs. the core (shame) self (14). However, despite empirical evidence for their distinctness (15, 16), shame and embarrassment are not always distinguished unequivocally, and, as a result, when many researchers speak of embarrassment, it is more accurate to think of shame (17).

Shame in the context of skin disease may arise from the experience of stigma (18). Stigma refers both to social reactions to attributes seen as degrading or devaluating (e.g., blemished skin), and to the internalization of such devaluation, termed self-stigma (19). Self-stigma and shame are thus closely related, both involving the devaluation of self, and are sometimes used interchangeably (20, 21). The impacts of stigma in skin diseases have been reviewed elsewhere (18, 22), whereas shame and self-stigma have not been investigated separately in skin diseases.

Kellett and Gilbert (7) also explore the impact of social difficulties and the importance of attractiveness on body shame reactions. In the context of body shame reactions, Gilbert (13) defines it as shame related to one’s own body, particularly concerning skin. In society, clear skin is idealized as a feature of “desirable individuals” (p. 10), and blemished or diseased skin can be perceived as a sign of poor overall health. Consequently, those affected may fear eliciting negative emotions like fear, anger, or disgust in others, potentially diminishing their desirability in various aspects, notably sexually.

Despite the importance of shame and self-disgust for the connections between social challenges, wellbeing, and symptom exacerbation posited in the bio-psycho-social model, the influence of these emotions on the wellbeing and treatment of individuals with skin disorders has received limited attention. Thus, this paper’s primary goal is to review existing literature, specifically focusing on the evidence supporting shame and self-disgust as psychological consequences and potential enhancers of inflammatory skin diseases. Reviewing the evidence will help identify gaps in the literature and guide further research into the psychological burdens and treatment of patients with skin diseases.

In various studies with patients suffering from atopic eczema or psoriasis vulgaris, the beneficial effects of combined dermatological and psychosocial interventions on the improvement of the skin condition, reduction of scratching frequency, and psychosocial parameters have been demonstrated (23). Good results are also obtained in approaches like relaxation, breathing, and art therapy, or psychodynamic catathymic image perception (24). Cognitive therapies focus on the dysfunctional appraisal of stressful events (25). Most approaches, however, lack a focus on challenging emotions such as shame and self-disgust (23). Modern psychotherapy has increasingly embraced mindfulness techniques, derived from Buddhism, such as mindfulness-based stress reduction (MBSR) and mindfulness-based therapies (MBT). These approaches adapt mindfulness from Buddhism to promote acceptance of current situations, reduce mental distress, and enhance overall psychological wellbeing. Stress-related skin conditions can benefit from these mindfulness practices, as they help reduce the mental noise and foster wisdom, ultimately increasing tolerance to stress and improving skin health (26). Additionally, self-compassion, a key concept in compassion-focused therapy (CFT), involves viewing oneself kindly and empathetically during challenging times, recognizing the universality of suffering, and mindfully accepting it (27). Unlike shame, which entails self-devaluation and a harsh self-critical relationship, self-compassion nurtures a loving, understanding, and forgiving self-relationship (28). By promoting better self-regulation and motives to alleviate suffering, mindfulness and self-compassion interventions can effectively address pathological shame and self-disgust in the context of skin diseases. As such, the second objective of this study is to review existing literature on the scientific evidence for using compassion-based or mindfulness-based therapies to address self-disgust and shame in individuals with skin diseases.

Studies were selected using the inclusion and exclusion criteria defined prior to the literature search. Inclusion criterion 1 included studies investigating emotions of shame (or self-stigmatization or embarrassment) or self-disgust or experience of disgust in the context of (psycho-)dermatological diseases (psoriasis, acne, atopic eczema). Criterion 2 included studies investigating mindfulness-based or compassion-focused-therapy regarding the emotions shame or self-disgust in patients with dermatological diseases (psoriasis, acne, atopic eczema). We did not define any excluding design parameters and only included studies focusing on adult populations (≥ 18 year).

Furthermore, we excluded pharmaceutical studies, quality assessments of clinical instruments or questionnaires, studies linking other types of emotions (e.g., nausea or anxiety) to skin diseases, and studies focusing on other types of dermatological diseases (e.g., sexually infectious diseases or skin picking). Additionally, as the effects of mindfulness interventions for improving quality of life (30) and experience of stigma in patients with skin diseases (18, 22) have recently been reviewed, studies with a primary focus on quality of life or stigmatization (without differentiating aspects of stigma) in the context of dermatological diseases were excluded. Studies examining mindfulness or self-compassion as traits or variables in therapy research were also excluded, a comprehensive review for the context of dermatological diseases was recently published (31). Studies examining compassion or mindfulness strategies outside of the context of dermatological diseases, or emotions of shame or disgust, were also excluded.

Based on our criteria, search terms were defined and combined logically to build a search operator. We used wildcards to include multiple concrete forms of the same word-stems: [(skin disease) OR (skin condition*) OR (disease risk) OR (dermatolog*) OR (acne) OR (eczema) OR (psoriasis)] AND {(shame) OR (disgust) OR (mindfulness) OR (compassion) OR (self-compassion) OR (bodily suffering) OR [(emotion*) AND (psycho*) AND (psychotherap*)] OR [(emotion*) AND (psycho*) AND (dermatolog*)]}. PubMed provides an option to add a NOT-operator. This was added for the following terms: NOT sexual abuse[Title/Abstract] NOT childhood[Title/Abstract] NOT dement*[Title/Abstract] NOT HIV/AIDS[Title/Abstract] NOT HIV[Title/Abstract] NOT breast cancer[Title]. The search results were combined using reference management software.

The systematic search was conducted in January 2022 via the databases PubMed, Web of Science and PSYINDEX and yielded N = 6,505 studies (n = 2,097 Doublettes). One study [(32), retrieved via Google Scholar] was published later in 2022 and was subsequently added to the search results. One relevant study (32) was excluded by our search operator because it contained the word “childhood” in the abstract.

The screening of the results was conducted between January and September 2022 (see Figure 2 for the PRISMA flow chart). A random selection of 496 studies was screened independently by all three reviewers based on the inclusion/exclusion criteria outlined above. The remaining studies were split equally and randomly between the three reviewers and screened accordingly. The set of randomly selected studies was used to estimate the inter-rater reliability. Although all three reviewers agreed concerning a binary decision (in-/exclusion) for 96.6% of the studies, the inter-rater reliability of the study selection was weak (k_fleiss = 0.359). Disagreements regarding the selection existed in the case of n = 17 studies and were discussed by all co-authors. Further inspection showed that two studies with relation to the quality of life also contained aspects of the emotion of embarrassment (33, 34) and were thus considered relevant. Furthermore, the inclusion and exclusion criteria related to social anxiety [included; (35, 36)], feelings of stigma [included; (35, 37, 38)], and skin picking [excluded; (39)] were interpreted differently by the reviewers. After discussing and resolving the disagreements, the agreement of study selection was 97.5% with substantial inter-rater reliability (k_fleiss = 0.659). One study (40) was falsely excluded in the screening and included in the review process thanks to one reviewer’s comment. All studies for which reviewers were not able to resolve their disagreements were included in the next step of retrieving the full manuscripts.

The full manuscripts of the remaining studies were subsequently retrieved. Studies were excluded if the full text was not available (n = 11), not written in English or German (n = 3), had a focus on skin disease or emotion that did not fit the inclusion criteria (n = 36), did not include an adult sample (n = 2), or investigated mindfulness and self-compassion as traits or not in relation to disgust or shame (n = 21). The main results across each group of studies were then summarized for a synthesis of the main outcomes.

The risk of bias was assessed independently using the NHLBI quality assessment tool (41). The tool consists of a catalog of questions that ask key questions about the internal validity of the respective study. There is a separate, suitable list of questions for each study type (controlled intervention studies, systematic reviews and Meta-Analyses, Observational Cohort, Case-Control Studies, etc.). Each point is queried with yes/no questions (unsuitable or non-answerable questions are answered with NA or “not reported”) and categorized as “good,” “fair” or “poor” (no quantification) according to predefined rules. Five independent reviewers rated the studies according to the applicable criteria. The detailed results of the risk of bias assessment can be found in the Supplementary Table 1. Systematic Reviews and Meta-Analyses often exhibited poor quality, raising concerns about the reliability of their findings. Controlled Intervention Studies, on the other hand, presented a heterogeneous picture ranging from poor to good quality, indicating the need for more standardized methodologies. Most studies fell within the category of Observational Cohort and Cross-Sectional Studies. These studies demonstrated varying degrees of quality, generally falling within the fair to good range. Additionally, a selection of qualitative studies was also included in the analysis contributing to the diversity of the evidence base. Based on the COREQ-Assessment (42) they showed fair to good quality.

Most of the literature that has examined shame, embarrassment, and self-stigma in dermatological conditions and that was included in the review comprised studies that examined patients with psoriasis. A total of 33 out of 46 included studies (72%) focussed exclusively or i.a., on psoriasis, while fewer studies focussing on acne (9 studies, 19%) or atopic eczema (4 studies 8.7%) were found.

Several questionnaire studies show that people with skin diseases displayed high levels of shame (17, 43–46), albeit not general shame (47) [see review by (48)]; skin shame (48); social shame (49). In a cross-sectional study with 166 psoriasis patients, Jankowiak et al. (50) showed that higher levels of shame were especially found in cases with visible skin lesions [see review by (51)] and that older patients reported less shame.

In addition, questionnaire studies found high levels of embarrassment (17, 33, 43, 45, 46, 52–55) associated with high self-consciousness about the skin disease (17, 56, 57), as well as high levels of self-stigma (17, 34, 58) in people with skin diseases. Again, visible lesions (e.g., scars) were associated with more embarrassment (59), and in psoriasis patients, this was even more acute than in people suffering from atopic eczema (60). Additionally, in a meta-analysis of ten qualitative studies of people with various dermatological conditions, emotional experience with embarrassment and shame emerged as one of the main themes (61). In one study, shame experience was also highlighted as the unifying factor between psoriasis and acne inversa patients in particular (62).

Lahousen et al. (32) found that patients with psoriasis reported significantly higher levels of skin-related shame and disgust than healthy controls, as well as more negative appraisals of self-touching and parental touching. Interestingly, severity of skin condition was unrelated to shame and disgust. A qualitative study also found that people suffering from skin diseases had an impaired self-image and low self-esteem (17, 63, 64). In a study on sexual problems in psoriasis, the majority of men reported feeling embarrassed and less attractive due to skin lesions, and at least occasionally ashamed with sexual partners (65). Psoriasis patients often cited feelings of being stared at, and others’ erroneous beliefs that the disease was contagious, as stressors (65, 66). These feelings may cause avoidant behavior, thus perpetuating social exclusion and explaining the link between shame, stigmatization, and depression as well as lower quality of life (67).

The study by Ginsburg and Link (37) showed that the fear of social exclusion harbored by psoriasis patients is not completely unjustified: 19% of patients experienced episodes of gross rejection as a result of their psoriasis. These experiences were accompanied by feelings of stigmatization. Magin et al. (68) also found embarrassment and low self-esteem as a result of teasing and bullying in people with dermatological conditions while Schielein et al. (69) showed that the main reason affected patients avoided sexual activity was shame and fear of rejection [see also (70)]. Since these feelings are fundamentally associated with social withdrawal and depression, Vladut and Kállay (71) call for multidisciplinary treatment in their review.

In connection with psoriasis, Ginsburg and Link (38) worked out six dimensions of self-stigma via a questionnaire study: the anticipation of rejection, a feeling of being flawed, sensitivity to others’ attitudes, guilt and shame, secretiveness, and positive attitudes. The authors suggested that a high experience of stigma might be associated with increased non-compliance with treatment and thus symptom exacerbation.

In a study by George et al. (72), what patients found helpful in dealing with the fear of social exclusion was active listening, shared decision-making, and communication of hope.

The state of research on disgust in dermatological diseases is considerably less comprehensive than that on shame and embarrassment. Mento et al. (73) also came to this conclusion in a literature review, according to which anger and disgust are neglected in studies. In a qualitative study, Wahl et al. (74) show that patients with psoriasis describe their bodies (especially in the case of visible skin rashes) as “offensive” and regard themselves as “unclean, infectious, disgusting, leprous, ugly, unattractive, strange, big, or different.” [see also (67)]. In an ethnographic qualitative study in different countries, dermatological patients described themselves with disgust and self-loathing (75).

In a questionnaire study, over 60% of patients with psoriasis reported experiencing strong self-disgust (76), and the findings showed that sex, age, depression, and perceived stigmatization were predictors of self-disgust whereby the relationship between stigmatization and depression was mediated by self-disgust. Moreover, there is evidence that dermatological patients experience disgust in others differently from skin-healthy people. In an approach-avoidance task, patients with psoriasis and their significant others more strongly avoided faces displaying disgust, but not other emotions, compared to controls (40). In an fMRI study by Kleyn et al. (77), psoriasis patients showed a reduced ability to recall faces with disgust reactions compared to controls. The authors concluded that this related to learned coping mechanisms to protect themselves from the reaction of disgust in others.

Although few studies to date have examined the effects of compassion-focused therapy on shame or disgust in skin conditions, empirical evidence supports the potential of CFT for reducing shame and enhancing treatment for patients with skin diseases. In a two-week randomized controlled trial (RCT) on 75 patients with facial acne who experienced skin-related distress and varying levels of depression, Kelly et al. (78) found that two compassion-focused interventions significantly reduced shame, as well as skin discomfort and depression, in comparison to a passive control. More mixed results were found in a four-week compassion focused self-help program (79). In this single-arm feasibility study with a small sample, two patients with initially high levels of shame and self-criticism reported significant reductions of shame and self-criticism at the end of the program, while two patients with relatively lower baseline levels experienced significantly increased levels of shame following the intervention (79). Thus, the limited evidence mostly supports the potential of CFT as an approach for individuals with skin diseases, particularly in reducing shame, self-criticism, and psychological distress.

For the effects of mindfulness-based approaches on shame and disgust in the context of skin disease, our search yielded only one study comparing MBT against CFT. In a feasibility RCT, Muftin et al. (80) tested a mindfulness self-help online program against a CFT program in 130 patients with psoriasis. Results showed that both four-week programs were acceptable and helpful in reducing shame and improving quality of life, suggesting that MBT may have comparable potential to CFT in alleviating shame and distress in patients with skin conditions.