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Keywords:

  • atopic dermatitis;
  • psoriasis;
  • psychopathology

Abstract

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Conclusions
  7. References

Background  There is a vast literature describing the association between psoriasis, atopic dermatitis (AD) and psychological distress. Some of these studies were uncontrolled and others used non-dermatological diseases as control, but only a few used chronic skin diseases as controls.

Objective  To compare well being, psychopathology and coping strategies of psoriatic, AD and healthy controls in a prospective case-control study.

Methods  Thirty-seven psoriatic patients and 31 AD patients were recruited from the Hadassah Ein Karem Hospital, Jerusalem, Israel, outpatient and inward clinic. The participants in the control group were 31 healthy workers and volunteers with no dermatological diseases from Kaplan Hospital, Rehovot, Israel. We used self-report questionnaires [Mental Health Inventory (MHI) and Adjustment to Chronic Skin Diseases Questionnaire (ACSD)], a projective technique (Hand Test) and assessment tools (Clinical Global Impression).

Results  Psoriatic patients experienced reduced well being (= 0.007) and more anxiety and depression (= 0.018) than normal controls. Psoriatic patients also displayed more severe psychopathology (= 0.039) a more passive attitude towards life, and loss of meaning in life (= 0.001) as measured by the projective technique compared with AD patients and normal controls.

Conclusions  We propose two explanations, derived from the psychological and the psycho-neuro-immunological domains. First, greater mental distress in psoriasis is because of the greater stigma it bears compared with AD. Alternatively, we hypothesize that the psoriatic inflammatory process may possibly have a direct central nervous system effect.


Introduction

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Conclusions
  7. References

Psoriasis is a chronic, relapsing inflammatory skin disease with a prevalence of 2.2%.1 While the aetiology remains to be fully elucidated, psoriasis is now regarded as a T-cell-dependent autoimmune disease, in which both genetic and environmental factors play an important role.2

Atopic dermatitis (AD) is a chronic, pruritic, inflammatory disease of unknown origin. The prevalence of AD is rising and currently affecting up to 15–20% of young children3 and 1–3% of adults.4 AD is a multifactorial disease, caused by a genetic predisposition and triggered by environmental factors. Thus, mutations in the filaggrin genes are considered to lead to transepidermal penetration of environmental allergens, increased transepidermal water-loss and inflammation.5

Psychosocial aspects in psoriasis have been well reviewed in three studies: Gupta et al.6, Ginsburg7 and Fortune et al.8 Many studies document the disruptive impact psoriasis has on patients’ lives. It is detrimental to body image9,10 and sexual functioning.11 Patients report having difficulties establishing social contacts and relationships.12 Psoriatic patients experience interpersonal anxiety along with shame and embarrassment, difficulties at work (such as limited opportunities), difficulty in functioning, family friction and depression.13

Many studies have dealt with the association between psoriasis and psychological distress. Patients with psoriasis were found to be more depressed than controls when utilizing the Beck Depression Inventory, and to have generally higher rates of depression or psychopathology than patients with lichen planus, leprosy and vitiligo. The percentage of psoriatic patients suffering from depression in these studies ranged from 22% to 58%14,15 Another study found a greater prevalence of depression and suicidal thoughts among patients with severe psoriasis compared with patients with acne, alopecia areata, AD or general medical conditions.16 Gupta et al.,17showed that the degree of depression increased with the degree of pruritus, which in itself was not related to psoriasis severity. Gupta et al.18 also reported that perception of stigmatization was the most significant factor in predicting depression in psoriasis.

Anxiety among psoriatic patients is even more common than depression. Richards et al.19 found that 43% of psoriatic outpatients were diagnosed with anxiety, a rate higher than other diseases such as cancer.20 Social anxiety/avoidance is reported to be higher in patients with psoriasis than in patients with AD, contact dermatitis, acne or vitiligo.21

Many studies implicate the role of stress in precipitating and exacerbating psoriasis. While some of these studies were uncontrolled,22–24 others used non-dermatological diseases as controls,25,26 and only a few used chronic dermatological diseases as controls.

In her review, Buske-Kirschbaum et al.27 showed that AD has a great impact on the mental health and quality of life of those suffering from the disease as a result of intense itching, unpredictability of the disease and feeling of disfigurement caused by the skin lesions. Positive correlations were found between pruritus severity and depression28 and between learned-scratch-response and anxiety.29 Several studies showed the severity of AD symptoms to be altered by stress.30,31 Prior studies suffered from methodological problems referring only to retrospective life events. More recent studies have shown that even minor everyday stressors reported the day before assessment can affect and predict symptom severity.32 Psychosocial stress and symptomatology might be bidirectionally related. Gil et al.33 found that AD children experienced increased levels of distress as a consequence of the chronic illness and the amount of stress was positively correlated with the skin condition, intensity of scratching or medication taken. Buske-Kirschbaum et al.27 concluded that it is not clear whether stress aggravates the skin condition, whether the symptom severity elevates the stress level or whether an additional factor increases both of them. Schmitt et al.34 found an independent association between AD and attention-deficit/hyperactivity disorder (ADHD) in a population-based study of children and adolescents, possibly related to AD severity. The authors state that it is unclear what the possible causal relationship or the association directions are. It remains unclear whether the observed association is as a result of shared aetiological factors, or whether itching, sleep disturbance or psychosocial stressors found in AD might induce or exacerbate ADHD symptoms in a subgroup of patients.

Although several studies indicate an association between psoriasis, AD and psychopathological problems, only a few have used chronic dermatological diseases as controls. In all of the studies reviewed above, researchers made use of clinical interviews and self-report questionnaires to study distress, psychopathology and psychological well-being. To the best of our knowledge, projective technique has not been used until now in dermatological studies. Projective techniques are psychological testing in which the subject is confronted with a set of stimuli, mostly pictures or inkblots, His response represents his own associations and ideas of what might be in the picture. There is no correct, definite or expected answer. Responses are considered as reflecting deeper layers of mental functioning, those which are not tapped by clinical questioning or self-report questionnaires.

The purpose of the present study was to assess and compare psychopathology, well being and coping strategies among patients suffering from psoriasis, AD and healthy controls. Assessment used self-reporting measures and a ‘projective’ technique.

Methods

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Conclusions
  7. References

Participants

The participants of the study were 37 psoriatic patients, 31 AD patients and 31 controls. The psoriatic and AD patients were recruited from the dermatologic department and outpatient clinic of Hadassah University Hospital, Jerusalem, Israel. The participants in the control group were healthy workers and volunteers, with no dermatological diseases of Kaplan Medical Center, Rehovot, Israel. Exclusion criteria included patients not fluent in Hebrew, patients under the age of 18 and patients receiving biological or immunosuppressive therapies that potentially could affect the mood. The groups were balanced in their demographic characteristics: no significant differences were found among the three groups in age, gender, marital status, country of origin, education and income (Table 1). In addition, no significant differences were found in age of illness onset or years since diagnosis between psoriatic and AD patients (Table 2). The study was approved by the Hadassah Medical Center’s ethics committee for clinical trials and informed consent was obtained from all participants, following an explanation of the study.

Table 1.   Study population
 Psoriasis (n = 37)Atopic dermatitis (n = 31)Control (n = 31)F-/χ2-valueP-value
  1. ns, not significant.

Age49.5 (16.3)41.7 (18.8)41.2 (11.6)2.9ns
Gender, n (%)
 Male15 (40.5)15 (48.4)15 (48.4)  
 Female22 (59.5)16 (51.6)16 (51.6)0.6ns
Marital status, n (%)
 Single7 (18.9)9 (29.0)5 (16.7)  
 Married24 (64.920 (64.5)22 (73.3)  
 Divorced3 (8.1)2 (6.5)3 (10)  
 Widowed3 (8.1)006.7ns
Country of origin, n (%)
 Israel22 (59.5)21 (67.7)20 (66.7)  
 America-W. Europe4 (10.8)3 (9.7)1 (3.3)  
 East Europe6 (16.2)4 (12.9)5 (16.7)  
 Asia-Africa5 (13.5)3 (9.7)4 (13.3)1.9ns
Education, n (%)
 High school19 (51.4)10 (32.3)11 (36.7)  
 Undergraduate6 (16.2)6 (19.4)4 (13.3)  
 Graduated12 (32.4)15 (48.4)15 (50)3.5ns
Income, n (%)
 Lower than average9 (24.3)7 (22.6)8 (26.5)  
 Average16 (43.2)15 (48.4)15 (50)  
 Higher than average12 (32.4)9 (29)7 (23.3)0.8ns
Table 2.   Comparison between psoriatic, atopic dermatitis and controls on the variables of the study
 Psoriasis (n = 37)Atopic dermatitis (n = 31)Control (n = 31)F-/χ2-valueP-valueM-W K-WP-value
  1. SCORAD, Severity Scoring of Atopic Dermatitis; CGI, Clinical Global Impression; MHI, Mental Health Inventory; ACSD, Adjustment to Chronic Skin Diseases Questionnaire; PASI, Psoriasis Area and Severity Index; M-W, Mann–Whitney test; K-W, Kruskal–Wallis test; ns, not significant; N/A, not applicable.

  2. *One tailed.

Age of illness onset33.9 (16.7)25.8 (21.6) 1.73ns396ns
Duration of illness16.1 (15)15.9 (16.9) 0.062ns503ns
SCORAD/PASI14.9 (12.6)40.0 (9.2) N/A N/A 
Need to scratch2.57 (3.04)4.42 (3.07) −2.50.015378.50.013
CGI4.2 (1.3)4.3 (0.9) −0.19ns511ns
MHI
 Well being51.1 (13.8)53.3 (11.9)60.5 (10.5)5.10.0079.50.006
 Psychological distress61.4 (22.5)55.7 (18.2)48.8 (12.1)3.90.0256.30.042
 Mental health total157.7 (34.7)165.5 (28.2)179.8 (21.0)4.80.0108.30.013
ACSD
 Social anxiety/avoidance33.8 (19.3)26.6 (10.5) 2.00.028*481.5ns
 Itch-scratch cycle19.6 (9.7)21.5 (9.0) −0.8ns471.5ns
 Helplessness21.6 (11.4)18.1 (8.3) 1.5ns488ns
 Anxious-depressive mood19.1 (8.1)17.0 (7.4) 1.1ns468ns
 Impact on quality of life13.1 (8.9)10.3 (3.8) 1.70.046*498.5ns
Hand test
 Direction4.8 (6.5)5.2 (5.4)9.5 (8.2)4.90.0099.00.010
 Acquisition4.2 (5.8)5.3 (8.0)1.4 (4.0)3.30.0406.60.038
 Description2.2 (4.5)1.2 (2.8)0.0 (0.0)4.00.0217.40.018
 Failure4.0 (6.3)1.8 (3.7)1.3 (3.4)3.00.0534.0ns
Interpersonal44.0 (13.0)50.2 (17.1)56.2 (14.1)5.90.00410.10.006
Environmental32.1 (16.2)32.0 (17.6)23.9 (12.1)2.9ns4.6ns
Maladjustive17.0 (14.0)14.5 (12.4)18.5 (12.9)0.7ns1.8ns
Withdrawal6.9 (7.7)3.2 (4.6)1.3 (3.4)8.5<0.00112.40.001
 Pathological index30.8 (17.9)21.0 (16.0)21.1 (13.8)4.30.0176.60.035

Instruments

Self-report questionnaires
  • 1
     A Socio-Demographic Questionnaire was compiled to assess age, marital status, country of origin, education, income, age at onset of illness and duration of illness.
  • 2
     The ACSD was designed by Stangier, Ehlers and Gieler21 to assess patients’ adaptation to chronic skin disorders. It consists of 51 items arranged in five sub-scales: social anxiety/avoidance, itch-scratch cycle, helplessness, anxious-depressive mood and impact on quality of life. The questionnaire showed high test–retest reliability and construct validity. In our study, the internal consistency of the scale was high (α = 0.97).
  • 3
     The MHI is a 38-item questionnaire composed of two inversely correlated sub-scales: 24 items of psychological distress including anxiety, depression and loss of behavioural-emotional control and 14 items of well being including general positive affect and emotional ties. Psychometric support was found for the use of a total score of all 38 items.35 The two sub-scales are scored inversely so that higher total scoring reflects greater well being. In our study, the internal consistency of the scale was high (α = 0.97).
Assessment tools
  • 1
     The Clinical Global Impression – Severity Scale (CGI) developed by Guy36, is a clinician observational scale to assess global severity of illness. The scale scores range from 1, ‘normal, no illness’ to 7, ‘seriously ill’. The scale has high inter-rater reliability (0.75–0.90).36
  • 2
     The Hand Test is a projective test aimed to assess patients’ coping strategies. The test consists of ten cards depicting a single hand in different positions. The cards are presented consecutively in a standardized order and subjects are requested to answer a single question: ‘What does this hand look like it might be doing?’ Answers are classified in 15 subcategories which combine to form four categories: (1) interpersonal (consisted of subcategories; affection, dependence, communication, exhibition, direction and aggression); (2) environmental (acquisition, active and passive); (3) maladjustive (tension, crippled and fear) and (4) Withdrawal (description, bizarre and failure). The test has high test–retest reliability and criterion validity.37
  • 3
     The Psoriasis Area and Severity Index (PASI) is based on four different parameters: erythema, scaling, thickness and itching combined with the area of affected skin in four anatomical areas of the body.38
  • 4
     Visual Analogue Scale (VAS) is a 100 mm long line representing intensity of itching. One side represents the lowest intensity of itching and the other is the highest itching intensity. Patients are required to mark a spot that represents their itching intensity. The score consists of the length in millimetres.
  • 5
     The Severity Scoring of Atopic Dermatitis (SCORAD) combines six clinical features of disease intensity: erythema, oedema, oozing, excoriations, lichenification and xerosis with subjective signs, such as, itching and insomnia.39

Statistical analyses

We used t-test for independent samples and Mann–Whitney tests (M-W) to compare psoriatic patients with AD patients and one-way analyses of variance (anova) and Kruskal–Wallis tests to compare among the three groups. Tukey and M-W were used to perform post hoc comparisons of each pair of groups. Chi-square values were calculated to find differences between the groups in categorical variables. Two-tail significance levels were provided except otherwise indicated. All statistical calculations were performed using spss 17.0 for Windows.

Results

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Conclusions
  7. References

Study population

Means and standard deviations of psoriatic, AD and control participants on age of onset and duration of illness, SCORAD/PASI, CGI, MHI, Hand Test and ACSD are presented in Table 2.

Severity of illness

The intensity of pruritus, according to the VAS, was higher in AD than in psoriatic patients. Mean values of severity of diseases (SCORAD and PASI Score) depicted moderate forms of the disease in both AD and psoriatic patients (Table 2).

Self-report questionnaires

Post hoc Tukey comparisons performed after analysis of variance showed significant differences between the psoriatic and the control group in the MHI Scale: psoriatic patients obtained significantly higher scores than the control group in the psychological distress scale of the MHI which includes anxiety, depression and loss of behavioural-emotional control (post hoc Tukey comparisons: = 0.018) and they obtained significantly lower scores on well being (Tukey: = 0.007) and mental health total score (Tukey: = 0.007) than the control group. These results were replicated by the nonparametric tests.

Atopic dermatitis patients – although suffering more from itching than the psoriatic patients – showed no significant differences with the control group in terms of total mental health, well being or psychological distress. There were no significant differences between psoriatic and AD patients in terms of psychological distress, well being or mental health total score.

The ACSD was administered to psoriatic and AD patients and not to the control group and therefore t-tests were performed only between the first two groups (see Table 2). Psoriatic patients reported significantly more social anxiety/avoidance (= 0.028, one tailed) and a greater impact on quality of life (= 0.046, one tailed) than AD patients on the ACSD, but these results were not replicated by the nonparametric tests. No significant differences were found between psoriatic and AD patients in the itch-scratch cycle, helplessness and anxious-depressed mood scales.

Projective test

Regarding the subcategories of the Hand Test, psoriatic patients provided less Direction responses (responses involving dominating, directing or influencing the activities of others) compared with controls as indicated by analysis of variance and post hoc Tukey tests (= 0.013) as well as nonparametric tests (see Table 2). Psoriatic patients gave significantly more Description responses (representing an inability to project an appropriate action, the subject can do no more than acknowledge the presence of the hand) compared with the control group (post hoc Tukey comparisons: = 0.016). Finally, psoriatic patients failed more to give any response to particular cards compared with the control group, but this result was not replicated by the nonparametric tests.

Atopic dermatitis patients provided less Direction (Tukey: = 0.034) and more Acquisition responses (responses involving an attempt to obtain a goal, but without accomplishing it, Tukey: = 0.038) compared with control subjects. No significant differences were found between psoriatic and AD patients in the frequency of Direction, Description or Acquisition responses.

Psoriatic subjects provided less Interpersonal responses (involving relations with other people) than controls as indicated by anova and post hoc Tukey (= 0.003) and nonparametric tests. Psoriatic patients provided more Withdrawal responses (responses reflecting an abandonment of meaningful or effective life-roles) than the control group (Tukey: = 0.001). As indicated by the post hoc Tukey comparison test, psoriatic patients were higher on the Pathological Index (the sum of Maladjustive responses and two times the Withdrawal responses, which provides an overall estimate of the total amount of pathology), than normal controls (Tukey: = 0.039). Psoriatic patients provided significantly more Withdrawal responses than the AD group (Tukey: = 0.026) and had a significantly higher Pathological Index than AD patients (Tukey: = 0.037).

Conclusions

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Conclusions
  7. References

Our results show that psoriatic patients experience more psychopathology than normal controls as assessed by self-reported measures and by the projective instrument of mental health. Psoriatic patients reported more anxiety, more depression and loss of behavioural control than normal controls. They also reported reduced well being compared with the control group. The findings from the self-report questionnaires were confirmed by the projective test. Psoriatic patients displayed in the projective technique more severe psychopathology, a more passive attitude towards life and are generally less effective or competent. They have lower involvement with people and feel greater loss of meaning in life compared with both AD patients and normal controls.

To explain these findings, we suggest two completely different explanations, one psychosocial and the other psycho-neuro-immunological. The literature suggests that psoriatic patients suffer from greater stigmatization than other skin disorders. Vardy et al.40 compared 100 psoriatic patients with 100 patients with ‘mixed skin problems’. They found that although there was no difference in disease severity, psoriatic patients reported more ‘experienced stigma’ than the other patients. Psoriatic patients’ quality of life was found to be influenced more by the experienced stigma than by the severity of the disorder. Psoriatic patients report having limited opportunities at work13 and to suffer more social discomfort and job discrimination compared with patients suffering from other skin disorders.41 Accordingly, the fear of negative evaluation has been reported to be higher in psoriasis compared with AD, contact dermatitis and acne.16

Thus, according to the psychosocial hypothesis, the reason for the more severe psychological reaction is the greater stigma psoriatic patients experience compared with patients with other skin disorders.

An alternative explanation to the differences found between psoriasis and AD may lie in the growing field of psycho-neuro-immunology. There is ample evidence to support the importance of psycho-neuro-immunological aspects of psoriasis and AD.2,25 Their similarities and differences will be discussed briefly.

The classical TH1 and TH2 paradigm, classifying psoriasis as a TH1 disease and AD as a TH2 disease has been revolutionized by the discovery of TH-17 cells, which are a helper-cell subset, that synthesize interleukin (IL)-17 and IL-22. Blauvelt2, in his review of the pathogenesis and therapy of psoriasis, emphasizes the role of TH-17 cells in this disease. Zheng42 showed that IL-23 induces marked hyperplasia in epidermal keratinocytes in murine skin and suggests that this effect is mediated through IL-22 produced by TH-17 cells.

Guttman-Yassky et al.,43 found a reduced genomic expression of IL-23/TH-17 and Interferon-γ in AD as compared with psoriasis. Psoriasis is associated in approximately one-third of the cases with psoriatic arthritis. Several studies have also shown an association of psoriasis with obesity, hypertension, coronary heart disease, hyperlipidaemia, type 2 diabetes and osteoporosis.44–48 The increased risk of comorbidities could possibly be attributable to the effects of chronic inflammatory changes, particularly infiltrates of T cells and pro-inflammatory cytokines in different organs.49

Spah50 has shown a common immune-pathogenic mechanism of inflammation in atherosclerosis and psoriasis. Traditionally, it was thought that obesity and metabolic syndromes are increased in psoriasis because of patient characteristics: introspection, less social interactions, increased alcohol and food consumption and less desire to exercise.51 However, it is not inconceivable that common genetic factors could also play a role. Finally, it is interesting to speculate whether possible CNS involvement can be found in the psycho-neuro-immunological process discussed above.

Depression is not currently perceived as an immuno-mediated disease and pharmacological treatment focuses primarily on the neurotransmitter system of serotonin, noradrenaline and dopamine. However, Lewitus et al.52 suggest that depression might indeed be an immune disease and developed a novel immunization with CNS-related antigens in mice, as a therapeutic mean to treat depression.

Yu et al.,53 showed that serotonine-5-hydroxitriptamine-2A receptor activation suppresses tumour necrosis alpha induced inflammation. Etanecerpt, infliximab and adalimumab, three biological treatments that affect tumour necrosis factor, have all been reported to improve depression in psoriatic patients.54–56 This leads us to hypothesize that TNF activation in psoriasis could possibly contribute to the development of depression through a psycho-neuro-immunological process.

In conclusion, further studies are needed to elucidate the pathophysiology of the psoriatic patient’s psychological behaviour.

References

  1. Top of page
  2. Abstract
  3. Introduction
  4. Methods
  5. Results
  6. Conclusions
  7. References