Attentional bias for psoriasis-specific and psychosocial threat in patients with psoriasis

Attentional bias in psoriasis: The role of processing time and emotional valence

PURPOSE

The present study explored whether people with psoriasis display an attentional bias towards disease-related threat words and whether this bias occurs relatively early during the phase of stimulus disengagement, or during a later maintained attention phase dominated by controlled strategic processes. We also explored the degree to which attentional bias is dependent on the emotional valence of control words.

METHODS

Individuals with psoriasis and matched controls took part in 4 online experiments. Participants completed a spatial cueing paradigm using disease-related threat words and control words as cues, in order to obtain reaction time estimates of attentional bias.

RESULTS

We did not observe evidence for attentional bias when control words were matched with threat words for emotional valence, regardless of whether processing time for the cues was limited (Experiment 1: SOA = 250 ms) or extended (Experiment 2: SOA = 1050 ms). We also did not observe evidence for attentional bias when control words of positive valence were used, but processing time was limited (Experiment 3). An attentional bias was only observed (p = .012, Cohen's d = .37) when sufficient processing time was available and positively-valanced control words were used (Experiment 4).

CONCLUSION

Rather than showing large and generalized AB effects as predicted by previous accounts, our results tentatively suggest that AB in psoriasis is restricted to situations where participants have ample processing time and threat words are easily distinguishable from control words on the basis of emotional valence. The pattern of results suggests that attentional bias in psoriasis is best characterized as a relatively slow strategic process.

Association of primary focal hyperhidrosis with anxiety induced by sweating: A cross-sectional study of Japanese university students focusing on the severity of hyperhidrosis and site of sweating

Hyperhidrosis significantly reduces patients' quality of life, with many reporting feeling highly anxious. However, the relationship between hyperhidrosis and anxiety induced by sweating has not been examined in detail. The current study examined the relationship between: (1) the presence of hyperhidrosis symptoms, (2) hyperhidrosis severity, and (3) the sites of the most sweating and anxiety induced by sweating. A cross-sectional web-based survey was conducted among university students, and 1080 consenting participants (600 males and 480 females; mean age, 18.8 years) were included in the analysis. The survey items were: (1) diagnostic criteria for hyperhidrosis, (2) Hyperhidrosis Disease Severity Scale, (3) presence of anxiety induced by sweating, and (4) site of the most sweating. The results of multiple logistic regression analysis adjusted for sex and age showed that the odds ratio (OR) for anxiety induced by sweating was significantly higher in participants who screened positive for hyperhidrosis than in those who screened negative (OR, 9.72 [95% CI, 5.80-16.27]). The OR of anxiety induced by sweating was 7.11 (95% CI, 3.99-12.65) for mild/moderate hyperhidrosis and 23.46 (95% CI, 7.15-76.93) for severe hyperhidrosis, compared with those who screened negative for hyperhidrosis. Compared with those who screened negative for hyperhidrosis, the OR for anxiety induced by sweating in those with the palmar, plantar, axillary, and head/face as the site of the most sweating was 7.74 (95% CI, 3.91-15.33), 14.86 (95% CI, 1.83-120.58), 16.92 (95% CI, 5.95-48.14), and 5.38 (95% CI, 1.39-20.74), respectively. Our findings suggest that participants who screened positive for hyperhidrosis, mild/moderate or severe, are at a higher risk of anxiety induced by sweating than participants who screened negative for hyperhidrosis.

No preconscious attentional bias towards itch in healthy individuals

Rapidly attending towards potentially harmful stimuli to prevent possible damage to the body is a critical component of adaptive behavior. Research suggests that individuals display an attentional bias, i.e., preferential allocation of attention, for consciously perceived bodily sensations that signal potential threat, like itch or pain. Evidence is not yet clear whether an attentional bias also exists for stimuli that have been presented for such a short duration that they do not enter the stream of consciousness. This study investigated whether a preconscious attentional bias towards itch-related pictures exists in 127 healthy participants and whether this can be influenced by priming with mild itch-related stimuli compared to control stimuli. Mild itch was induced with von Frey monofilaments and scratching sounds, while control stimuli where of matched modalities but neutral. Attentional bias was measured with a subliminal pictorial dot-probe task. Moreover, we investigated how attentional inhibition of irrelevant information and the ability to switch between different tasks, i.e., cognitive flexibility, contribute to the emergence of an attentional bias. Attentional inhibition was measured with a Flanker paradigm and cognitive flexibility was measured with a cued-switching paradigm. Contrary to our expectations, results showed that participants attention was not biased towards the itch-related pictures, in facts, attention was significantly drawn towards the neutral pictures. In addition, no effect of the itch-related priming was observed. Finally, this effect was not influenced by participants’ attentional inhibition and cognitive flexibility. Therefore, we have no evidence for a preconscious attentional bias towards itch stimuli. The role of preconscious attentional bias in patients with chronic itch should be investigated in future studies.

Prevalence and Odds of Anxiety Disorders and Anxiety Symptoms in Children and Adults with Psoriasis: Systematic Review and Meta-analysi

The magnitude of the association between psoriasis and depression has been evaluated, but not that between psoriasis and anxiety. The aim of this systematic review and meta-analysis was to examine the prevalence and odds of anxiety disorders and symptoms in patients with psoriasis. Five medical databases (Cochrane Database, EMBASE, PubMed, PsychINFO, ScienceDirect) were searched for relevant literature. A total of 101 eligible articles were identified. Meta-analysis revealed different prevalence rates depending on the type of anxiety disorder: 15% [95% confidence interval [CI] 9–21] for social anxiety disorder, 11% [9–14] for generalized anxiety disorder, and 9% [95% CI 8–10] for unspecified anxiety disorder. There were insufficient studies assessing other anxiety disorders to be able to draw any conclusions on their true prevalence. Meta-analysis also showed a high prevalence of anxiety symptoms (34% [95% CI 32–37]). Case-control studies showed a positive association between psoriasis and unspecified anxiety disorder (odds ratio 1.48 [1.18; 1.85]) and between psoriasis and anxiety symptoms (odds ratio 2.51 [2.02; 3.12]). All meta-analyses revealed an important heterogeneity, which could be explained in each case by methodological factors. The results of this study raise the necessity of screening for the presence of anxiety disorders, as previously recommended for depressive disorders, in patients with psoriasis and, if necessary, to refer such patients for evaluation by a mental health professional and appropriate treatment.

Druggable Targets and Compounds with Both Antinociceptive and Antipruritic Effects

Pain and itch are both important manifestations of various disorders, such as herpes zoster, atopic dermatitis, and psoriasis. Growing evidence suggests that both sensations have shared mediators, overlapping neural circuitry, and similarities in sensitization processes. In fact, pain and itch coexist in some disorders. Determining pharmaceutical agents and targets for treating pain and itch concurrently is of scientific and clinical relevance. Here we review the neurobiology of pain and itch and discuss the pharmaceutical targets as well as novel compounds effective for the concurrent treatment of these sensations.

Acute Itch Induces Attentional Avoidance of Itch-related Information

Attention is known to modulate itch intensity. In contrast, the reverse relationship, i.e. the degree to which the presence of an acute itch affects attention, is currently not well understood. The aims of this study were to investigate whether acute itch induces an attentional bias towards or away from visual itch-related stimuli, and if so, whether it occurs in the early or later stages of processing. A volunteer sample of 60 healthy individuals were subjected to a skin prick (either histamine or placebo), followed by completion of a spatial cueing paradigm using itch-related and neutral words as cues, in order to obtain reaction time estimates of attentional bias. The results suggest that experience of acute itch induces attentional avoidance of visual itch threats. This attentional avoidance occurs at a later processing stage in the form of facilitated disengagement of attention from itch and/or delayed disengagement from neutral information.

Attentional Bias Modification Training for Itch: A Proof-of-Principle Study in Healthy Individuals

Itch draws our attention to allow imposing action against bodily harm (e.g., remove insects). At the same time, itch is found to interfere with ongoing tasks and daily life goals. Despite the key role of attention in itch processing, interventions that train individuals to automatically disengage attention from itch cues are lacking. The present proof-of-principle attention bias modification (ABM) training study was aimed at investigating whether attention to itch as well as sensitivity to mild itch can be changed. Healthy volunteers were randomized over three ABM-training conditions. Training was done via a modified pictorial dot-probe task. In particular, participants were trained to look away from itch stimuli (n = 38), toward itch stimuli (n = 40) or not trained toward or away from itch at all (sham training, n = 38). The effects of the ABM-training were tested primarily on attention to itch pictures. Secondarily, it was investigated whether training effects generalized to alterations in attention to itch words and mechanical itch sensitivity. The ABM-training did not alter attention toward the itch pictures, and there was no moderation by baseline levels of attention bias for itch. Also, attention bias to the itch words and itch sensitivity were not affected by the ABM-training. This study was a first step toward trainings to change attention toward itch. Further research is warranted to optimize ABM-training methodology, for example increasing motivation of participants. Eventually, an optimized training could be used in patient populations who suffer most from distraction by their symptoms of itch.

Clinical Trial Registration: Identifier: NL6134 (NTR6273). The website URL is: https://www.trialregister.nl/

Risk of Depression in Patients With Psoriatic Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Previous systematic reviews have assessed the prevalence and odds ratio (OR) of depression for patients with psoriatic disease. Due to probable bidirectional effects, prevalence and prevalence ORs are difficult to interpret. No prior reviews have quantified the relative risk (RR) of depression following a diagnosis of psoriatic disease.

OBJECTIVE

To estimate the RR of depression in individuals with psoriasis and in psoriatic arthritis (PsA), clear-to-moderate psoriasis, and moderate-to-severe psoriasis subgroups.

METHODS

Observational studies investigating the risk of depression in adults with psoriatic disease were systematically searched for in Medline, EMBASE, PsycINFO, and CINAHL databases; 4989 unique references were screened. Studies that reported measures of incident depression in psoriasis patients were included. Thirty-one studies were included into the systematic review, of which 17 were meta-analyzed. Random effects models were employed to synthesize relevant data. Sources of heterogeneity were explored with subgroup analysis and meta-regression.

RESULTS

Seventeen studies were included in meta-analyses. The pooled RR of depression in psoriasis patients compared to nonpsoriasis controls was 1.48 (95% CI: 1.16-1.89). Heterogeneity was high (I² = 99.8%). Subgroup analysis and meta-regression did not indicate that PsA status or psoriasis severity (clear-to-mild, moderate-to-severe) were sources of heterogeneity. No evidence of publication bias was found.

CONCLUSIONS

This review demonstrates that the risk of depression is greater in patients with psoriasis and PsA. Future research should focus on developing strategies to address the mental health needs of this patient population for depression, including primary prevention, earlier detection, and treatment strategies.

What are the barriers to physical activity in patients with chronic plaque psoriasis?

Background

Psoriasis is associated with an increased risk of cardiovascular disease. Despite recommendation that exercise is important for cardiorespiratory fitness, patients with psoriasis avoid participation in physical activities for reasons that are, as yet, unclear.

Objectives

This study investigated the relationship between psoriasis‐specific experiences and self‐reported patterns of exercise, hypothesizing that individuals with psoriasis are less likely to engage in physical activity for reasons that are related to their psoriasis.

Methods

In total 404 patients with chronic plaque psoriasis were recruited. History, examination and physical activity were assessed for each participant.

Results

Overall, 52·8% (n = 188) of patients with psoriasis aged 18–65 years and 66% (n = 37) of those aged > 65 years engaged in less than the recommended amount of physical activity for cardiorespiratory fitness. As the severity and psychosocial impact of psoriasis increased, the participation in exercise (of all intensities) decreased. There was a significant negative correlation between Psoriasis Area and Severity Index and total activity in women aged 18–65 years (r = −0·19, 95% confidence interval −0·36 to 0; P = 0·04) and a significant negative correlation between physical activity and Dermatology Life Quality Index (DLQI) in all participants (r = −0·11, 95% confidence interval −0·21 to 0; P = 0·04). Individual components of the DLQI identified barriers to physical activity including skin sensitivity and reluctance to participate in leisure activities.

Conclusions

Psoriasis‐specific factors – severity, skin sensitivity, clothing choice, participation in social/leisure activities, and treatments – contribute to exercise avoidance and may augment the increased risk of cardiovascular disease in patients with psoriasis.

What is already known about this topic?

Psoriasis is associated with an increased prevalence of risk factors for cardiovascular disease.

Despite recommendation that exercise is important for cardiorespiratory fitness, patients with moderate‐to-severe psoriasis participate in very little physical exercise for reasons that are, as yet, unclear.

What does this study add?

This study quantifies the significant lack of engagement with exercise in the population of people with psoriasis.

Physical activity in those with psoriasis is significantly influenced by psoriasis severity, quality of life and a number of previously unrecognized psoriasis‐specific barriers.

What is the translational message?

Supporting patients with psoriasis to undertake regular physical activity could directly benefit weight management, cardiovascular disease and risk of metabolic syndrome, and increase wellbeing and psychosocial functioning.

Linked Comment:Jarrett.Br J Dermatol 2020; 183:988–989.

Plain language summary available online

What is new in the psychology of chronic itch?

Itch is often regarded as unpleasant or bothersome and is accompanied by symptoms of distress and impairments in daily life. The biopsychosocial model of chronic itch describes how psychological factors can contribute to the improvement or exacerbation of chronic itch and related scratching behaviour. Recent research underlines the important role of cognitive-affective information processing, such as attention, affect and expectancies. This may not only play a role for acute itch states, but may particularly apply to the process of itch chronification, for example, due to the vicious cycle in which these factors shape the experience of itch. The present paper focuses on new insights into the relation between itch and the cognitive-affective factors of attention, affect and expectancies. These factors are thought to play a possible aggravating role in itch in the long term and have received increasing attention in the recent empirical literature on maintaining and exacerbating factors for chronic physical symptoms. Possible psychophysiological and neurobiological pathways regarding these factors are discussed, as well as possible intervention methods.

Cognitive load and emotional processing in psoriasis: a thermal imaging study

Psoriasis is a chronic dermatologic disease which is frequently associated with psychological distress. Although studies suggest a relationship between this condition and difficulties in emotion regulation, behavioral and physiological evidence about this link is scarce. We measured implicit emotion regulation abilities of psoriasis patients and a healthy control group by examining the impact of distracting emotional (positive, negative or neutral) images on a working memory task ("Emotional N-Back") which could present high (2-back) or low (1-back) cognitive workload. Moreover, we used Functional Infrared Thermal Imaging to record participants' facial temperature and obtain a measure of the activation of the autonomic system. Rising of temperature over the peri-orbital areas and the nose tip are believed to reflect the activation and the de-activation of the sympathetic system, respectively. Patients scored higher than controls on the "Lack of emotional clarity" sub-scale of the Difficulties in Emotion Regulation Scale. Compared to controls, who performed much better in the low vs. high cognitive load condition, patients showed a smaller accuracy difference between the two conditions. Moreover, patients showed less sympathetic (lower peri-orbital and higher nasal tip temperature) activity (especially in the negative and neutral blocks) during the high vs. low cognitive load condition, suggesting that the former condition might be less emotionally demanding for them. Patients benefit more than controls from the load-dependent interference effect when dealing with emotional information; thus, therapeutic techniques aiming at teaching how to use cognitive strategies to downregulate emotions might be particularly appropriated for them.

Automatic processes and self-regulation of illness

Research on the Commonsense Self-Regulation Model has emphasised reflective/conscious perceptual processes regarding illness threat (beliefs about symptoms, consequences, timeline, and curability) in predicting and changing coping behaviours. Understanding of illness self-regulation and avenues for intervention might be enriched by consideration of automatic processes that influence the recognition and identification of illness, response to illness, and ongoing management. This article adopts an integrative approach to (1) outline the theoretical importance of implicit processes in patients' self-regulation of illness and methods to study them; (2) review research evidence for these processes, including interventions tested to modify them; and (3) outline avenues for future research. A substantial body of research on implicit processes (cognitive bias and interpretational bias) in illness maintenance in chronic illness has recently been extended to detection and interpretation of acute illness and new perspectives relating to the self-system. There is encouraging evidence that cognitive accessibility of coping and implicit attitudes may impact upon coping behaviours. Procedures that strategically automatise coping responses and create habits have considerable promise. We outline an agenda for future research in which health psychology accepts the challenge posed by the interplay of the reflective and associative systems in promoting effective self-regulation of illness.

Do Tonic Itch and Pain Stimuli Draw Attention towards Their Location?

BACKGROUND

Although itch and pain are distinct experiences, both are unpleasant, may demand attention, and interfere with daily activities. Research investigating the role of attention in tonic itch and pain stimuli, particularly whether attention is drawn to the stimulus location, is scarce.

METHODS

In the somatosensory attention task, fifty-three healthy participants were exposed to 35-second electrical itch or pain stimuli on either the left or right wrist. Participants responded as quickly as possible to visual targets appearing at the stimulated location (ipsilateral trials) or the arm without stimulation (contralateral trials). During control blocks, participants performed the visual task without stimulation. Attention allocation at the itch and pain location is inferred when responses are faster ipsilaterally than contralaterally.

RESULTS

Results did not indicate that attention was directed towards or away from the itch and pain location. Notwithstanding, participants were slower during itch and pain than during control blocks.

CONCLUSIONS

In contrast with our hypotheses, no indications were found for spatial attention allocation towards the somatosensory stimuli. This may relate to dynamic shifts in attention over the time course of the tonic sensations. Our secondary finding that itch and pain interfere with task performance is in-line with attention theories of bodily perception.

Inflammation, Self-Regulation, and Health: An Immunologic Model of Self-Regulatory Failure

Self-regulation is a fundamental human process that refers to multiple complex methods by which individuals pursue goals in the face of distractions. Whereas superior self-regulation predicts better academic achievement, relationship quality, financial and career success, and lifespan health, poor self-regulation increases a person's risk for negative outcomes in each of these domains and can ultimately presage early mortality. Given its centrality to understanding the human condition, a large body of research has examined cognitive, emotional, and behavioral aspects of self-regulation. In contrast, relatively little attention has been paid to specific biologic processes that may underlie self-regulation. We address this latter issue in the present review by examining the growing body of research showing that components of the immune system involved in inflammation can alter neural, cognitive, and motivational processes that lead to impaired self-regulation and poor health. Based on these findings, we propose an integrated, multilevel model that describes how inflammation may cause widespread biobehavioral alterations that promote self-regulatory failure. This immunologic model of self-regulatory failure has implications for understanding how biological and behavioral factors interact to influence self-regulation. The model also suggests new ways of reducing disease risk and enhancing human potential by targeting inflammatory processes that affect self-regulation.

Attentional processing of itch

Itch is a prevalent somatosensory symptom that can be highly disabling, because it is likely to draw attention and, as a result, may interfere with the performance of daily activities. Yet, research experimentally investigating attention to itch is lacking. In this study we aimed to investigate attentional processing of itch using multiple behavioral attention tasks. Forty-one healthy participants performed (1) a modified Stroop task with itch-related words, (2) a dot-probe task with itch-related pictures, and (3) a recently developed somatosensory attention task in which the effect of experimentally induced itch on the localization of visual targets was examined. Additionally, a number of self-report questionnaires related to somatosensory attentional processing were administered. Results indicated that participants’ attention was biased toward itch-related words and pictures assessed by means of the dot-probe and modified Stroop task, respectively. For the somatosensory attention task, results showed that itch did not significantly influence the allocation of attention. However, when taking into account the time course of attention during the itch stimulus, data suggested that participants tended to disengage attention away during the itch stimulus. This is the first study that indicates an attentional bias for itch, using methods that have previously been validated for other sensations such as pain. In addition, the newly developed somatosensory attention task may reflect the time course of attention toward a tonic itch stimulus.

The importance of mindfulness in psychosocial distress and quality of life in dermatology patients

BACKGROUND

Mindfulness, defined as purposively and nonjudgementally paying attention in the present moment, could be used within psychosocial interventions to reduce the distress associated with social anxiety and avoidance found in many skin conditions. However, little is known about the relationship between naturally occurring levels of mindfulness and distress in dermatology patients.

OBJECTIVES

To examine the relationship between mindfulness and psychosocial distress in a dermatological population. It was hypothesized that higher levels of mindfulness would be associated with lower levels of social anxiety, anxiety, depression and skin shame, and with better quality of life.

METHODS

Adult dermatology outpatients (n = 120) from one hospital completed items assessing subjective severity, skin shame, fear of negative evaluation, anxiety and depression, quality of life, and levels of mindfulness.

RESULTS

Considering depression, 14% reported mild, 5% moderate and 2·5% severe symptoms. For anxiety, 22% reported mild, 23% moderate and 6% severe symptoms. In addition, 33·4% reported clinically significant social anxiety. After controlling for subjective severity, mindfulness explained an additional 19% of the variance in depression, 39% in anxiety, 41% in social anxiety, 13% in skin shame and 6% in dermatological quality of life. One specific facet of mindfulness (acting with awareness) was found to be the most consistent predictor of distress.

CONCLUSIONS

The findings indicate that higher levels of mindfulness are associated with lower distress. This suggests that facilitating mindfulness may be helpful in reducing distress in dermatology patients, and the use of mindfulness techniques warrants further investigation.

How to Psychologically Minimize Scratching Impulses

Research in recent years, especially in the analgesic field, has intensively studied the placebo effect and its mechanisms. It has been shown that physical complaints can be efficiently reduced via learning and cognitive processes (conditioning and expectancies). However, despite evidence demonstrating a large variety of physiological similarities between pain and itch, the possible transfer of the analgesic placebo model to itch has not yet been widely discussed in research. This review therefore aims at highlighting potential transfers of placebo mechanisms to itch processes by demonstrating the therapeutic issues in pharmacological treatments for pruritus on a physiological basis and by discussing the impact of psychological mechanisms and psychological factors influencing itch sensations.

Risks of developing psychiatric disorders in pediatric patients with psoriasis

BACKGROUND

Symptoms of psoriasis can be embarrassing and distressing, and may increase risk of developing psychiatric disorders in young people.

OBJECTIVE

We sought to compare incidences of psychiatric disorders between pediatric patients with psoriasis and psoriasis-free control subjects.

METHODS

Patients (<18 years) with continuous health plan enrollment 6 months before and after first psoriasis diagnosis (index date) were selected (Thomson Reuters MarketScan database, 2000-2006 [Thomson Reuters, New York, NY]). Patients with psoriasis (N = 7404) were matched 1:5 on age and sex to psoriasis-free control subjects (N = 37,020). Patients were followed from index date to first diagnosis of a psychiatric disorder (ie, alcohol/drug abuse, depression, anxiety disorder, bipolar disorder, suicidal ideation, eating disorder), end of data availability, or disenrollment. Patients with psychiatric diagnoses or psychotropic medication use before the index date were excluded. Cox proportional hazard models controlling for age, sex, and comorbidities were used to estimate the effect of psoriasis on risks of developing psychiatric disorders.

RESULTS

Patients with psoriasis were significantly more at risk of developing psychiatric disorders versus control subjects (5.13% vs 4.07%; P = .0001; hazard ratio = 1.25; P = .0001), especially depression (3.01% vs 2.42%; P = .0036; hazard ratio = 1.25; P = .0053) and anxiety (1.81% vs 1.35%; P = .0048; hazard ratio = 1.32; P = .0045).

LIMITATIONS

Retrospective, observational studies of medical claims data are typically limited by overall quality and completeness of data and accuracy of coding for diagnoses and procedures.

CONCLUSIONS

Pediatric patients with psoriasis had an increased risk of developing psychiatric disorders, including depression and anxiety, compared with psoriasis-free control subjects.

A computerized Stroop task to assess cancer-related cognitive biases

Biases in processing information related to sources of stress have widely been demonstrated with the use of Stroop emotional color word tasks. One study reported such biases among women with histories of breast cancer in a first-degree relative (FH+) who were given a Stroop cancer word task. This study aimed to replicate and extend these findings with a computerized version of the task. Response latencies and errors were recorded during administration of the task to FH+ and FH- women. A cancer list and 5 comparison lists were administered. Results indicated that FH+ women exhibited longer response latencies for cancer words than did FH- women (p < 0.04), providing further support for cognitive biases in FH+ women. Confirming the psychometric properties of the task, lists exhibited high reliability for both latency (alphas 0.96-0.98) and error rate (alphas 0.61-0.79). In sum, results support the favorable psychometrics and predictive validity of the Stroop cancer word task.

Heterotopic pruritic conditioning and itch--analogous to DNIC in pain?

Pain can be endogenously modulated by heterotopic noxious conditioning stimulation (HNCS) through a mechanism which is known as diffuse noxious inhibitory control (DNIC). Since DNIC can be impaired in patients suffering from chronic pain, a comparable impaired itch inhibition may exist in patients suffering from chronic itch. The aim of the present study was to investigate whether heterotopic pruritic conditioning stimulation (HPCS) would display an impaired modulation of itch in patients suffering from chronic itch compared with healthy subjects. To this end, electrical stimuli were applied before and after histamine application (HPCS) to female patients with psoriasis and healthy female control subjects. Subjects reported the intensity of electrically evoked itch before and after HPCS. In order to replicate earlier findings for DNIC, electrically evoked pain was additionally investigated before and after cold stimulation (HNCS). As expected, the intensity of itch evoked by the electrical stimulus was significantly less after than before HPCS in healthy subjects, and the same was found for the intensity of electrically evoked pain after compared to before HNCS. Contrarily, in the patients levels of electrically evoked itch were significantly higher after than before HPCS, and no significant difference in pain intensity before and after HNCS was observed. In line with pain modulation, results suggest that there is a DNIC analogous mechanism for itch, i.e., diffuse pruritic inhibitory control (DPIC), which is impaired in patients with chronic itch, possibly due to a dysregulation of descending itch modulatory systems.

Dependency of illness evaluation on the social comparison context: findings with implicit measures of affective evaluation of asthma

OBJECTIVES

The affective dimension of illness representation plays an important role in asthma self-management. However, little is known about the stability of this affective representation across contexts. We explored the role of social comparison in this affective evaluation.

DESIGN AND METHODS

Participants included 20 individuals reporting an asthma diagnosis and 33 healthy controls. To measure asthma attitudes, we used three different versions of the Implicit Association Test (IAT), a single target IAT (ST-IAT) and two IATs with different social comparison standards for asthma evaluation (1) HIV and (2) diabetes. Reaction times to pair asthma with positive or negative word stimuli in the three IATs were compared in a repeated measure ANOVA. Furthermore, the relationship between affective evaluation, self-reported asthma-specific coping, and negative affect was explored.

RESULTS

Individuals reporting an asthma diagnosis showed a stronger negative evaluation of asthma than healthy individuals in the ST-IAT. This negative evaluation was positively related to the self-report of dysfunctional coping strategies. However, in the IAT introducing a downward social comparison with HIV, evaluation of asthma was less negative and no longer positively related to the report of dysfunctional coping.

CONCLUSION

Downward social comparison can buffer against negative affective evaluation of asthma. The context dependency of illness-related attitudes requires attention in future research and asthma management practice.

A sensitive body or a sensitive mind? Associations among somatic sensitization, cognitive sensitization, health worry, and subjective health complaints

OBJECTIVES

Psychobiological sensitization and health worry appear to be involved in the etiology of clinical manifestations of subjective health complaints (SHCs) via amplified processing of health-related information. However, it is not clear whether sensitization and health worry are also associated with common SHCs, which are extremely prevalent and are responsible for a large part of both human suffering and health care costs. In this study, we investigated whether SHCs are associated with health worry and two types of sensitization: cognitive health-related sensitization and somatic sensitization. We also examined whether health worry mediates the relationship between cognitive sensitization and SHCs and whether both levels of sensitization interact.

METHODS

A nonclinical sample of 47 female students completed questionnaires about their recent subjective health as well as health worry and underwent tests for cognitive sensitization, operationalized as Stroop interference and free recall performance, and somatic sensitization, operationalized as pain tolerance and pain threshold in a cold pressor task.

RESULTS

Severity of health complaints was positively related with recall of health-related stimuli, but not with Stroop interference, and with worrying about health complaints. In addition, worry mediated the relationship between recall bias and severity of health complaints. Both the number and severity of recent health complaints were associated with pain tolerance. Pain threshold was associated with Stroop interference for health-related information.

CONCLUSIONS

The results suggest that specific types of cognitive sensitization and somatic sensitization are associated with common health complaints and that worrying about one's complaints might play a role by enhancing biased memory of health-related information.

Pathogenesis and clinical features of psoriasis

Psoriasis, a papulosquamous skin disease, was originally thought of as a disorder primarily of epidermal keratinocytes, but is now recognised as one of the commonest immune-mediated disorders. Tumour necrosis factor alpha, dendritic cells, and T-cells all contribute substantially to its pathogenesis. In early-onset psoriasis (beginning before age 40 years), carriage of HLA-Cw6 and environmental triggers, such as beta-haemolytic streptococcal infections, are major determinants of disease expression. Moreover, at least nine chromosomal psoriasis susceptibility loci have been identified. Several clinical phenotypes of psoriasis are recognised, with chronic plaque (psoriasis vulgaris) accounting for 90% of cases. Comorbidities of psoriasis are attracting interest, and include impairment of quality of life and associated depressive illness, cardiovascular disease, and a seronegative arthritis known as psoriatic arthritis. A more complete understanding of underlying pathomechanisms is leading to new treatments, which will be discussed in the second part of this Series.

Response of the hypothalamic-pituitary-adrenal axis to psychological stress in patients with psoriasis

BACKGROUND

Psoriasis may, in some patients, be triggered and/or exacerbated by stress.

OBJECTIVES

As activation of the hypothalamic-pituitary-adrenal (HPA) axis is critical to a successful stress response we investigated this in patients with psoriasis.

METHODS

Forty patients with chronic plaque psoriasis and 40 age-matched normal controls experienced three randomly presented acute psychological stressors (cognitive, emotional and social). Serial serum cortisol, pulse rate and blood pressure assessments were undertaken at baseline and following each of the stressors. Salivary cortisol samples were collected at 09.00 h on the day of testing.

RESULTS

In control subjects there was a significant (r = 0.38; P < 0.05) correlation between pulse rate and serum cortisol level following the social performance stressor; this was not evident in the psoriasis group (r = 0.07; not significant). Patients who believed that their psoriasis was highly stress responsive had significantly lower salivary cortisol levels at baseline (P < 0.01) and lower serum cortisol levels following the social performance stressor (P = 0.016) than patients with nonstress-responsive disease who believed that stress had no impact. In contrast, there was no difference between the groups for change in pulse rate poststressor.

CONCLUSIONS

This study shows that patients with psoriasis, and in particular those whose disease appears to be stress responsive, exhibit an altered HPA response to acute social stress. The implication is that such patients may perhaps be primed to flares of their psoriasis. Whether this is genetically predetermined and/or a consequence of the distress of living with psoriasis remains to be determined.

Psychologic Factors in Psoriasis: Consequences, Mechanisms, and Interventions

The article examines the English-language research literature concerning psychologic aspects of psoriasis published since 1995. The literature is concerned with (1) the consequences of psoriasis in terms of quality of life, disability, depression, anxiety, and stigmatization and factors that may predict such outcomes; (2) potential mechanisms of the interaction between psychologic factors, stress, and the pathophysiology of psoriasis; and (3) examination of the clinical utility of psychologic interventions on extent of psoriasis and psychologic distress. The implications of the findings are discussed with reference to future directions for research and practice.

Psoriasis: future research needs and goals for the twenty-first century

Psoriasis research is entering a new era. Progress in delineating immunogenetics and pathomechanisms of disease brings with it a need to understand fully the clinical spectrum of disease and integrate phenotype with genomics and proteomics. Involvement of patient groups and an understanding of the psychosocial aspects of psoriasis, particularly its significant impairment of quality of life, are keys to progress. The biologic revolution in therapy of inflammatory disease has embraced psoriasis bringing with it an urgent need for evidence-base, consensus on outcome measures, and long-term real-life studies.A concerted effort between academia, industry, and patients will take forward the understanding of, and therapy for, psoriasis.

Divergent Beliefs About Psoriasis Are Associated with Increased Psychological Distress

The psychological adjustment of patients with psoriasis has been studied extensively. By comparison, no research has focused on their partners. We examined illness representations of psoriasis held by patients and their partners, and investigated whether divergent beliefs were associated with psychological distress. Fifty-eight patients with chronic plaque psoriasis and their partners completed a range of psychological assessments including beliefs about the condition, anxiety, depression, and worry. Patients also completed a self-assessment of psoriasis severity. Patients with psoriasis had significantly higher levels of anxiety, depression, and worry than their partners (t's > 2.53, p's < .05). Multiple regression analysis indicated that divergence in patients' and partners' beliefs about emotional impact of psoriasis and chronicity of timeline accounted for a statistically significant (21.3%) proportion of the variance in depression for partners. Differences in views on the consequences of having psoriasis and the cyclical nature of the condition were also significantly associated with increased levels of worry in partners. Dissimilarity in particular aspects of illness representations are associated with increased psychological distress in particular for the partners of patients with psoriasis. The results illustrate the importance of concordance between patients' and partners' models of illness in relation to adjustment, and highlight the need to consider and collaborate with both patients and their partners in managing this challenging condition.