Evaluation of life quality in patients with psoriasis

Psoriasis is a disease that has a profound impact on all aspects of life quality because over years patients are faced not only with poor health, but also with a number of restrictions imposed by the disease in their professional, social and emotional life. The aim of the study was to assess the level of impairment to the life quality in patients with chronic plaque psoriasis in relation to the clinical status of the disease, disease duration, and age and gender of the examinees. The cross-sectional study was conducted at the Clinic for Skin and Venereal Diseases of the Clinical Center of Niš. The total sample consisted of 142 examinees, 82 in the primary group (patients with psoriasis), and 60 in the control group (healthy volunteers). In order to assess the impact of psoriasis on life quality and compare it to the life quality of healthy population, the DLQI questionnaire (Dermatology Life Quality Index)was used and the disease severity was estimated based on the value of the PASI score (Psoriasis Area and Severity Index). The results showed that the groups of examinees differ appreciably in self-assessment in all five dimensions of life quality.In patients with psoriasis, there was statistically significantly lower life quality as a reflection of the disease severity and subjective perceptions of the disease impact and treatment impact, but also as a result of a number of restrictions in daily functioning caused by the disease.Patients with a severer clinical status gave low ratings to their ability to function in all areas covered by the DLQI questionnaire, especially in the symptoms and feelings subscale.The results of our study indicate the importance of a multidisciplinary approach in the treatment of patients with psoriasis and the possibility of introducing a supportive therapy, which would, along with a regular dermatological therapy, notably improve the life quality of these patients.

or spontaneous remissions and exacerbations of varying duration alter, thus substantially affecting all aspects of a patient's life (Langley, Krueger, & Griffiths, 2005;Schön & Boehncke, 2005).Psoriasis affects 1 to 3% of the world population, and studies suggest that another 0,4% to 2,3% of adults have symptoms of the disease, although it is not clinically diagnosed.The highest morbidity rate has been found in the Scandinavian countries (3%), and the lowest among the Indians of North America (0,5%) (Schön & Boehncke, 2005).The data for our country are not systematized, and reports commonly mention 150000 patients with psoriasis (Ugrinović, Dostanić, & Karadaglić, 2000).The disease occurs at any age, equally in both sexes and can be present at birth but it can also manifest itself in old age.When it comes to age, bimodal onset of the disease is generally recognized.Type I starts before or in one's forties and is associated with hereditary factors and a tendency towards a more severe and generalized course of the disease.Type I has occurred in 75% of cases.Type II is manifested after the age of 40, showing little or no correlation with hereditary factors.Apart from having a milder clinical course, it is also sporadic (Naldi & Gambini, 2007;Schön & Boehncke, 2005).
Chronic plaque psoriasis is an erythemato-squamous relapsing disease, which apart from obvious physical changes on the skin also leads to psychosomatic illnesses that are often more obvious than clinical symptoms of the disease (Reimus, Vingerhoets, Soons, & Korstanje, 2007).Changes on the skin, which are difficult to disguise if they are not covered by clothing, cause major concern with appearance, maladjustment, depression and a sense of inferiority, which disrupts the self-evaluation and well-being of the patient (Reimus et al., 2007).Patients with psoriasis often manifest psychological suffering due to the loss of self-confidence and self-esteem, and the skin condition often worsens in accordance with a negative emotional state and as a reaction to stress (Fortune, Richards, & Griffiths, 2005;Reimus et al., 2007).Emotional stress can worsen the clinical state and pose a serious problem in the treatment if it is not recognized as an exacerbating factor.Numerous clinical studies have shown that approximately 30 to 40% of patients experience worsening of psoriasis due to stress.In children, the percentage is even higher and amounts to 90% (Fortune et al., 2005;Picardi, Mazzotti, Gaetano, & Cattaruzza, 2005).The physiological mechanism that connects stress, or the sympathetic nervous system, and the clinical manifestations of psoriasis is the influence of neuropeptides which are considered to be peripheral mediators of neurogenic components of psoriasis, and in particular substance P, whose level is significantly increased in conditions of stress (Mozzanica, Cattaneo, Vignati, & Finzi, 1994).The stress stimulates the release of substance P from unmyelinated nerve endings, which leads to an increase in the number of mastocytes in the dermis and starts their degranulation, vasodilation and keratinocyte proliferation as well as a range of biochemical processes that result in exacerbation of psoriasis (Mozzanica et al., 1994).Based on clinical characteristics, psoriasis can be considered a source of chronic emotional stress.Stress as a "trigger" in the emergence or worsening of the disease (a psychosomatic impact) and, on the other hand, the daily "little" stress caused by visible changes on the skin cause a number of limitations in daily functioning, which often creates a vicious circle (circulus vitiosus) that affects the deterioration of mental condition, which, consequently, aggravates the skin condition (a psychosomatic impact) (Gupta, Gupta, Ellis, & Voorhees, 1990;Koo & Pham, 1992).
The study hypothesis was that individuals with psoriasis have a significantly lower life quality compared to healthy population.It was also expected that life quality scores of patients with psoriasis are connected to their age, gender and disease severity, and that the highest scores will be linked to the subscale of symptoms and feelings.The aim of this study was to point out the considerable impairment of life quality in patients with psoriasis, as well as a need for an interdisciplinary collaboration by a dermatologist, a psychologist and a psychiatrist in treating these patients.

Method Participants
The research involved 142 participants.The basic group consisted of 82 (57,7%) inpatients and outpatients with psoriasis vulgaris treated at the Clinic for Skin and Venereal Diseases of the Clinical Center Niš, who were diagnosed with this disease on the basis of modern and uniform diagnostic criteria,as well as on pathological examination, and the diagnosis was confirmed by experienced dermatologists.Homogenization of the basic group was performed on the basis of disease duration (one year from the diagnosis), sex and age of the examinees.The study did not include pregnant and lactating women, patients with arthropathic, erythrodermic or pustular psoriasis, those suffering from severe chronic or malignant diseases, or patients unfit for cooperation.The control group that represents a healthy population consisted of a non-clinical sample of 60 (42,3%) healthy volunteers without somatic and psychiatric diseases.The average age of the population was 51,70 ± 18,41 years.Basic and control groups were matched by age and gender.The study was designed as a crosssectional study and was conducted after obtaining the approval of the Ethics Committee of the Faculty of Medicine in Niš.

Measures
The survey used the following instruments: PASI (Psoriasis Area and Severity Index, Fredricksson & Pettersson, 1978), a questionnaire DLQI (Dermatology Life Quality Index, Finlay & Khan, 1994), and a general questionnaire with demographic and medical data which constructed for research purposes.Psoriasis Area and Severity Index (PASI) is applied to an objective and standardized assessment of disease severity and disease activity (Schmitt & Wozel, 2005).PASI is an instrument that measures the affection of the skin surface, localization and intensity of changes, and the obtained parameters are synthesized and expressed through a special formula whose result is the PASI score.The formula for calculating the PASI score numerically evaluates the intensity of erythema, infiltration and desquamation and they are graded on a scale from 0 to 4, where 0 -means the skin without pathological changes, 1indicates a slight intensity of changes, 2 -moderate, 3 -severe, and 4 -very severe intensity of changes.The surface of the skin affected by psoriatic lesions is expressed as a percentage, on a scale from 0 to 6 (0=0%, 1=<10%, 2=10-29%, 3=30-49%, 4=50-69%, 5= 70-89%, 6=90-100%).These values are determined for four anatomical regions of the body: head, upper limbs, trunk, lower limbs and then they are added and through a special formula transformed into the final PASI score.Its numerical value ranges from 0 (no change on the skin) to 72, which represents the maximum value of the PASI score (Schmitt & Wozel, 2005).PASI is the standard method for assessing the severity of psoriasis, adopted at the international level and available for dermatologists to use without formal permission of the copyright holder.In our study, the dermatologist assessed the PASI score, based on criteria for the analysis of clinical features of psoriasis proposed by Schmitt and Wozel (2005), mild psoriasis was classified as a PASI <7, moderate psoriasis between 7 and 12, and severe psoriasis as> 12.
To assess the impact of psoriasis on life quality and compare with life quality of the healthy population, the Dermatology Life Quality Index Questionnaire (DLQI) was used.DLQI is a simple and practical test, designed for assessing limitations in daily functioning caused by diseases of the skin (Finlay, 1997).It consists of 10 questions focused on different aspects of life quality and classified into five subscales: symptoms and feelings, daily activities, leisure, work and school, personal relationships and treatment.For each question four answers were offered that were scored from 0 to 3 (0 = not relevantnot at all, 1 = a little, 2 = a lot, very much = 3), and summarized results provide a range of scores ranging from 0 (no disease impact on life quality) to 30 (the most prominent effect of the disease on life quality).Total DLQI scores were classified as follows: 0-1 = no effect at all on patient's life, 2-5 = small effect on patient's life, 6-10 = moderate effect on patient's life, 11-20 = very large effect on patient's life, 21-30 = extremely large effect on patient's life.The questionnaire was designed to test people older than 16, and refers to the period of the week preceding the interview (Finlay, 1997).The evaluation of measuring characteristics of the questionnaire was expressed by the value of Cronbach alpha coefficient, which amounted to 0,90, and showed high reliability and validity of the selected measuring instrument.For the application of the DLQI questionnaire, which was translated into Serbian and culturally and linguistically adapted, we obtained the written consent of the author, Professor A. Finlay.For the purposes of this study, a general questionnaire with sociodemographic and anamnesis data was designed.
The evaluation of results obtained using the questionnaire was carried out in relation to the healthy volunteers, the age of patients and their gender and disease duration.The collected data were verified by the author, coded and entered into a specially formulated database.The paper applied Student's t-test, Chi-square test and Mann-Whitney U test.Data were analyzed using standard descriptive statistical methods (mean, standard deviation and percentage).Statistical analysis was performed by SPSS 16.0.The results are presented in tables and graphs, along with a text comment.

Results
The study group consisted of 142 individuals whose general characteristics are shown in Table 1.The average age of the population was 51,70 ± 18,41 years.The average age of patients with psoriasis was 53,80 ± 18,90 years, while the age of the control group was 48,76 ± 17,42 years.It was found that the patients' and control groups are equal in age of the examinees (z=1,752, p=0,080).In the examined groups there was no statistically significant difference in age between the sexes (z=1, 516, p=0,130; z=1,005, p=0,315).In the group of patients with psoriasis there were 48 male (58,5%) and 34 female participants (41,5%).In the control group, there were 35 male (58,3%) and 25 female participants (41,7%).Performed Chi-square test did not show a statistically notable difference in the distribution of participants by sex in the studied groups (χ2 = 0.001, p = 0.981) (Table 1).
Clinical characteristics of patients with psoriasis are shown in Table 2. Male patients were older (42,24 ± 16,46) than the female population (37,76 ± 14,85) at the time of the outbreak, but there was no statistically noteworthy difference (p=0,200).The mean duration of the disease was slightly higher in males compared to female participants (p=0,588).Female patients had considerably higher PASI scores compared to women with psoriasis(z=2,801, p=0,005) (Table 2).
According to disease severity expressed through the values of PASI scores, all patients were classified into three categories (Table 3).Based on the value of the PASI score it was determined that the studied population has 11 patients (13,4%) with a mild form of the disease (PASI<7), 26 patients (31,7%) with a moderately severe form of the disease (PASI 7-12) and 45 (54,9%) patients with severe psoriasis (PASI>12) (Table 3).
The data on life quality were obtained by using the DLQI questionnaire, and the scores are shown in Table 4.By using Mann-Whitney U test for independent samples, the results of the group of patients and the control group of healthy examinees were compared.A higher score in DLQI dimensions, which indicated greater impairment of life quality and a greater number of people experiencing difficulties, was a direct result of the disease.Examinees with psoriasis had significantly higher average scores in all dimensions of life quality compared to the healthy population.In patients, the highest DLQI score was related to symptoms and feelings, and the lowest for work and school.It was found that there was a statistically significant difference between the groups in mean scores for all DLQI dimensions, except for personal relationships.Patients had significantly higher levels of the total DLQI score compared to the healthy population (7,63±4,67 vs 2,43±1,43, z=6,789, p<0,001).(Table 4).The results indicating the disease have no effect at all on patients' lives in 6 patients (7,3%), have a small effect on patients' lives in 23 subjects (28,0%), have moderate effect on patients' lives in 33 subjects (40,2%) and have a very large effect on patients' lives in 20 patients (24,4%).
To determine the differences in the perception of limitations which the disease brings between sexes, their scores in all five dimensions of the DLQI questionnaire were compared and the results are shown in Table 5.The comparison of the scores for the different dimensions of the DLQI has shown that there is a statistically notable difference in the values of the scores related to work and school in relation to sex (z = 2,216, p = 0,027).Female patients had substantially higher values in this score compared to those of male participants.The total DLQI score was not significantly different between patients of different sexes (Table 5).
The correlation between the DLQI total score with the age of patients, duration and disease severity was investigated by the correlation analysis (Table 6).It was shown that there is no statistically important relationship between DLQI scores and the age of the patient (r=0,191, p=0,086), as well as the duration of the disease(r=0,039, p=0,730).The correlation analysis of the PASI score and the DLQI total score showed a statistically significant positive correlation between the total DLQI score and the PASI score(r=0,330, p=0,003) (Table 6).
The correlation between severity of psoriasis and life quality of patients was tested by Kruskal-Wallis's analysis of variance test, and the results are shown in Table 7.It was found that the severity considerably increased the value of DLQI scores that are related to symptoms and feelings (χ 2 =8,525, p=0,014).The post hoc analysis revealed that a statistically noteworthy difference was found between patients with a mild form and patients with severe psoriasis (z = 2,740, p = 0,006).Other components of the score, and the total DLQI scores were not substantially different in relation to the severity of the disease (Table 7).

Discussion
Psoriasis is a serious disease that has a verified social, psycho-emotional and economic impact on the livelihoods of those affected.A chronic and relapsing nature of the disease often leads to feelings of hopelessness, loss of selfesteem and a significantly restriction in daily activities, professional and sexual functioning (Fortune et al., 2005;Picardi et al., 2005;Reiumus et al., 2007).A substantial goal of the treatment is to reduce disease activity and to reduce the extent of changes to a level that does not consider ablyaffect the ability to work, or in any way interfere with the social life of the patient (Bhosle, Kulkarni, Feldman, & Balkrishnan, 2006).The effectiveness of the applied treatment procedure is estimated mainly based on doctor's subjective impressions, and the core indicators are reduced infiltration, desquamation and erythema in the affected areas of the skin (Bhosle et al., 2006;Fairhurst, Ashcroft, & Griffiths, 2005).However, it often happens that objectively evaluated clinical assessment of the dermatologist is not in accordance with the subjective assessment of the patient's condition.The aim of our study was to point out the significant degree of damage to life quality in patients with psoriasis.Also, by using standard procedures for assessing the severity of psoriasis, the PASI score and the DLQI questionnaire for assessing life quality, we wanted to examine the extent to which the disease duration and its severity affect life quality of patients and whether their age and gender substantially alter the perception of the disease.
The study included 142 examinees, 82 patients with chronic plaque psoriasis and the non-clinical sample of 60 healthy volunteers, without somatic and psychiatric diseases.The homogenization of the basic group was performed on the basis of disease duration (one year from diagnosis), sex and age of the participants.Basic and control groups were matched by age and gender.General and clinical characteristics of the patients are shown in Tables 1, 2 and 3.By using DLQI questionnaire, we examined life quality in patients with psoriasis and the control group (Table 4).A higher score in DLQI dimensions is indicating greater impairment of life quality and a higher number of difficulties a person faces daily due to his/her illness (Lewis& Finlay, 2004).Patients with psoriasis had significantly higher average scores in all dimensions of life quality compared to the healthy population (7,63±4,67 vs 2,43±1,43, z=6,978, p<0,001) (Table 4).Since the original questionnaire coding was such that a higher score indicates poorer life quality, the first hypothesis that patients with psoriasis have poorer life quality compared to the healthy population was confirmed.Patients with psoriasis had an average value of the DLQI score of 7,63, which is in the zone of a moderate impact on life quality (values from 6 to 10).Similar average values of DLQI scores above 7,2 to 10,0 for the patients with psoriasis were also found in the works of other authors, (Bronsard et al., 2010;Fairhurst et al., 2005).The highest DLQI score in patients has been linked to symptoms and feelings, which is associated with emotional problems and perceptions of stigma (Schmid-Ott, Schallmayer, & Calliess, 2007), which confirmed the second hypothesis.Our results confirmed previous findings (Bronsard et al., 2010;Lewis & Finlay, 2004).The lowest DLQI score is related to work and school, which is in line with the previous data from the literature (Lewis & Finlay, 2004;Pearce et al., 2006).The explanation for this finding could be related to the average age of patients (53,80±18,90) and the fact that time brought adaptation to the environment and social assimilation in the workplace.It was found that there was no statistically important difference between groups in the mean scores for all subscales of the DLQI, except for personal relationships.Comparing the scores for different dimensions of the DLQI in a group of patients with psoriasis showed a statistically notable difference in the subscale related to work and school and in relation to sex (Table 5).Women perceive their disease as a significant limiting factor in the performance of their duties.In a professional sense, men are better adapted to the limitations caused by the disease, which was also the conclusion of previous studies (Basavaraj, Navya, & Rashmi, 2011;Gaikwad, Deshpande, Raje, Dhamdhere, & Ghate, 2006).The correlation between the total DLQI score with the age of patients, disease duration and severity expressed by the PASI score did not show statistically prominent correlations (Table 6).Although there are studies that suggest that aging leads to deterioration in life quality, particularly in the functional dimension, our study did not confirm it (Basavaraj et al., 2011;Lewis & Finlay, 2004).The correlation analysis of the value of the PASI score and the DLQI total score showed a statistically significant positive correlation, while our third hypothesis is partially confirmed.Specifically, we found a statistically considerable association only between disease severity and total DLQI scores, whereas the correlation between the total DLQI score and disease duration, the age of the patient, as well as their gender was not statistically important.Also, it was found that the severity of the clinical status significantly modifies the perception of life quality.The results showed that increasing severity of the clinical status raises the value of DLQI scores that are related to symptoms and feelings, and this difference was statistically noteworthy between patients with a mild form of psoriasis and patients with severe psoriasis (Table 7).Most of the previous studies indicate a same conclusion (Bronsard et al., 2010;Reimus et al., 2007).
The limitations of this study are associated with the fact that the number of patients was relatively small for making general conclusions.The crosssection study also does not reflect the objective situation and the need to plan prospective studies will be based on monitoring a large group of patients over a longer period of time in order to give relevant results.Also, life quality as a multidimensional category must involve much more valid parameters than those covered by the DLQI questionnaire.

Conclusion
The classic paradigm of bio-psychosocial model of the disease has prompted numerous studies that have resulted in a sharp increase in interest in the role of psychological and social factors in health, i.e. disease.The outcome of these research papers is important theoretical and practical knowledge about the influence of psychosocial components of the expression and development of chronic cutaneous diseases.The study of life quality apart from enabling the inclusion of patients in assessing their health status also provides important information about functional disorders, and psychological and social status that patient is experiencing as a direct result of the disease.Psoriasis is a disease that modifies the patient's life in different domains.The complexity of discovering life quality is emphasized by the possible underestimation of patient's mental illnesses by doctors or overvaluation of psychologically induced discomfort that occurs in social or professional contacts of these patients.Perceived life quality is a key step in the strategy to improve life quality of patients with psoriasis.Achieving remission and withdrawal of clinical symptoms of the disease may not be the sole aim and outcome.The patient must be helped at the psychoemotional level by giving support and by devising a rehabilitation program that will allow re-socialization and overcoming of social prejudices, the establishment of a full control over life and satisfaction with one's own social identity.Superficial psychotherapy methods, psychodynamic psychotherapy, autogenic training, biofeedback techniques and behavioral techniques could significantly improve life quality in patients and allow them to cope with health problems more easily.Given that this is an incurable disease that considerably affects patient's life quality, the concept of individual and interdisciplinary approach to treatment that includes psychotherapy treatment could affect the disease activity, but also improve the working capacity of the patient and provide professional and psychosocial rehabilitation over a longer period of time.

Table 1
Baseline demographic characteristics # Mann-Whitney U test

Table 2
Clinical characteristics of patients with psoriasis # Mann-Whitney U test

Table 3
Severity of psoriasis

Table 4
Comparison DLQI dimension scores between psoriasis patients and healthy adults

Table 5
Comparison DLQI dimension scores between female and male psoriasis patients

Table 6
Correlation analysis DLQI scores, patient age, disease duration and PASI scores

Table 7
Correlation analysis DLQI scores and desaese severity # Kruskal-Wallis test, Post hoc Man-Whitney U test