Intro
Psoriasis is a chronic systemic inflammatory disease that involves mainly the skin
and joints, affecting 1-3% of the world population. 1 - 3 In Brazil,
there are still no studies on its incidence and prevalence, but it is estimated that
1% of the Brazilian population has psoriasis. 4 Its impact on quality of life (QoL) has been studied since
the 1970s, when Jobling observed that more than 80% of patients presented
difficulties in establishing social relations, considered the most daunting aspect
of their illness. 5 , 6 Since then, interest has increased in the quality of
life and psychosocial wellbeing of psoriasis patients. Many studies have shown that
psoriasis triggers feelings of depression, shame, and anxiety, culminating in social
isolation. 7 - 11 Al-Mazeedi et al. reported that
psoriasis inhibited new relations in 48.2% of patients, and two-thirds were
concerned about the reactions and perceptions of others in relation to their
condition. 8
One of the key points in maintaining QoL, as defined by the World Health
Organization, is sexuality. 12
Sexual dysfunction is characterized by lack of adequate functioning of one of the
phases comprising the sexual cycle. In women, sexual dysfunction is defined as
disorders of desire, libido, or arousal, pain or discomfort, and
anorgasmia. 13
Although sexual dysfunction is a common complaint, affecting 30 to 70% of psoriasis
patients, few studies have analyzed the impact of psoriasis and psoriatic arthritis
on quality of sexual life, and none has addressed the Brazilian
population. 14 , 15 The aim of this article was to
assess the occurrence of sexual dysfunction in psoriasis using a case-control study
with Brazilian women.
Methods
A case-control study was performed with a convenience sample consisting of patients
with a diagnosis of psoriasis (psoriasis group) treated at a specialized Dermatology
Outpatient Service at Hospital Universitário de Brasília (HUB) and
healthy volunteers (healthy control group), matched for age, recruited at the
Dermatology Outpatient Clinic of Hospital das Forças Armadas (HFA) from July
2011 to October 2012. The control group consisted of women that were accompanying
patients at the outpatient clinic and patients returning for follow-up, previously
treated and without clinical complaints at the time of recruitment.
The study was approved by the Institutional Review Board of Faculdade de Medicina,
Universidade de Brasília (case review 010/2011).
Inclusion criteria for all the women were: age 18 to 69 years, active sexual life,
and clinical diagnosis of psoriasis, as determined by the same physician, an
experienced dermatologist, and or clinical-pathology study. For the control group,
an inclusion criterion was the absence of diagnosis of psoriasis or psoriatic
arthritis.
Exclusion criteria were: gynecological disorder potentially affecting sexual function
(including vaginitis, endometriosis, chronic pelvic pain, malignant neoplasm,
uterine cervical dystopia, vaginism, and alterations of the pelvic anatomy);
pregnancy; prior psychiatric diagnosis or concurrent with psoriasis (depression,
anxiety, phobias, psychopathy); diagnosis of rheumatic diseases or others that
course with arthritis (rheumatoid arthritis, spondyloarthritis, microcrystalline
arthritis), which can cause confounding or doubt as to the diagnosis of possible
psoriatic arthritis; diagnosis of chronic, extensive skin disorders such as
dermatitis, pityriasis rubra pilaris, bullous dermatoses, vitiligo, ichthyosis, acne
grade two or greater, and genital mucocutaneous diseases.
After signing informed consent, all participants underwent a clinical assessment that
recorded epidemiological data like age, ethnicity, schooling, and marital status,
besides clinical data such as past medical history and use of medications. In
psoriasis patients, the location of the lesions was also verified (genital
involvement, ungual involvement, and involvement of exposed skin areas, the latter
defined for purposes of this study as lesions located on the face, scalp, and hands)
and extent of the disease, assessed by the Psoriasis Area Severity Index
(PASI). 16 Next, patients
were submitted to the version validated in Brazilian Portuguese of the Female Sexual
Function Index (FSFI) and the Medical Outcome Study 36-item Short Form Health Survey
(SF-36). 17 , 18 Finally, women with any complaints pertaining to
the joints were examined by an experienced rheumatologist (always the same
physician), in order to assess the presence of psoriatic arthritis, based on the
CASPAR classification criteria. 19
The FSFI is a questionnaire that aims to assess female sexual response through
analysis of the five domains of sexual function: desire and subjective arousal,
lubrication, orgasm, satisfaction, and pain/discomfort. Individual scores are
obtained by the sum of the items that include each domain (simple score), which are
multiplied by this domain's factor, furnishing the weighted score. The final score
(minimum two, maximum 36) is obtained by the sum of the weighted scores in each
domain. A total score of 26 or less indicates greater risk of sexual
dysfunction. 20
SF-36 is a 36-item questionnaire that assesses eight domains of QoL: physical
functioning, role physical, bodily pain, general health, vitality, social
functioning, role emotional, and mental health. The score for each domain varies
from zero to 100, where zero is the worst health status and 100 is the
best. 18
The sample calculation was done initially in a pilot study with 67 women (47 with
psoriasis and 20 controls), evaluating the variables obtained with the desire
indices from the FSFI by means of the Wilcoxon text with 95% confidence
interval, leading to 88% test power for a sample of 150 women with a difference
of one point.
Analyses of the association between variables used the R software, version 2.15.1
(R Foundation for Statistical Computing, Vienna, Austria. ISBN 3-900051-07-0,
URL http://www.R-project.org/ ). The Kolmogorov-Smirnov test for
normality was used to verify whether the sample's data showed normal
distribution. The distribution was considered normal if p>0.05. Analysis of
categorical variables was based on the chi-square test of independence. When
data for the variables were less than five, the p-value from the Monte Carlo
simulated Fisher's exact test was used, as proposed by Hope, 1968. 21 The association between
quantitative variables was investigated in two ways: a) by means of
categorization of the variables, followed by analysis using the chi-square test
or Monte Carlo simulated p-value; b) by calculation of Pearson's correlation
coefficient, when the variables showed two-tailed normal distribution, or
Spearman's rank correlation coefficient for cases that did not show this
distribution. Finally, analysis of covariance was applied to assess quantitative
target variables from FSFI and SF-36, adjusted for covariables that could
influence the study's results. The categories of some covariables were grouped
so as to increase the model's explanatory capacity and goodness of fit.
Statistical significance was set at 5%.
Results
The study's sample size was 150 women, of whom 75 in the control group and 75 in the
psoriasis group, both with mean age 45 years and standard deviation approximately 12
years. All the patients diagnosed with psoriasis were caucasian or of mixed races.
The control group included a few black and Asian-descendent women, but the vast
majority were caucasian or of mixed races (92%). In both groups, the majority of
women were married, but the proportion of unmarried women and those not living with
a partner (i.e., single, divorced, or widows) was higher (42.66%) in the psoriasis
group. As for education, the control group included predominantly women with more
than seven years of schooling, while the psoriasis group included mostly those with
one to seven years of schooling. Only two illiterate women participated in the
study, both with psoriasis.
As for clinical status of psoriasis, most of the patients presented psoriasis
vulgaris, and for disease site, 20% presented genital involvement, 33% ungual
involvement, and 30% with lesions on exposed areas. PASI scores varied from 0 to
21.4, with a median score of 3.6 (interquartile range, 6.3). Comorbidities were
present in 45% of the control group and 72% of the psoriasis group. Chi-square test
showed a statistically significant association between presence of comorbidities and
psoriasis (p=0.023). Rheumatological assessment was performed in 38 of the 75
patients diagnosed with psoriasis, of whom 16 had a diagnosis of fibromyalgia, ten
of psoriatic arthritis, and two of osteoarthritis; 31 patients denied any kind of
rheumatic manifestation. Tables 1 and 2 , respectively, show the psoriasis group's
clinical characteristics and analysis of comorbidities.
Clinical characteristics of psoriasis group
Lesions present on face, scalp, and hands
Assessment of comorbidities in the psoriasis group and control group
(chi-square test)
SAH - systemic arterial hypertension; DM -
diabetes mellitus
Analysis of covariance revealed significantly worse indices in the psoriasis
group, adjusted for age, skin color, schooling, and marital status in the
domains role physical (p=0.002), role emotional (p=0.029), and mental health
(p=0.021) ( Table 3 ).
Comparison of quality of life (SF-36) between the groups with and without
psoriasis, adjusted by age, ethnicity, schooling, and rital status
(analysis of covariance)
Adjusted for age, schooling, marital status, and ethnicity *
significance: p-value < 0.05
Forty-four patients (58.6%) and 29 controls (38.6%) showed FSFI score less than
or equal to 26, with a chi-square test with p-value 0.014, demonstrating higher
occurrence of sexual dysfunction in psoriasis patients, with 95% confidence.
Analysis of the association between diagnosis of psoriasis and each of the
domains (desire, arousal, lubrication, orgasm, satisfaction, and pain),
separately, adjusted for age, race, schooling, and marital status was done by
analysis of covariance. Table 4 shows
that the statistical difference was maintained, evidencing that the score in the
control group was higher than in the group of psoriasis patients for all the
domains.
Comparison of FSFI between the groups with and without psoriasis,
adjusted for age, ethnicity, schooling, and marital status (analysis of
covariance)
Results adjusted for age, race, schooling, and marital status *
significance: p-value <0.05
Sexual dysfunction showed a statistically significant association with the extent
of skin involvement (p-value=0.04). However, this association was not observed
when analyzing the different lesion sites by means of the chi-square test:
genital involvement was present in 25% of the women without sexual dysfunction
and in 19% of those with sexual dysfunction, p-value=0.55; ungual involvement in
32.3% of women without dysfunction and in 34.1% of women with sexual
dysfunction, p-value=0.868; and involvement of exposed skin areas in 39.3% of
women without dysfunction and in 27.9% of women with sexual dysfunction
(p-value=0.32).
The association between sexual dysfunction and comorbidities was analyzed by the
chi-square test in the psoriasis group (66.7% of women without dysfunction and
79% of women with sexual dysfunction presented comorbidity) and did not show a
statistically significant association (p=0.273). As for diagnosis of rheumatic
disease, assessed in 69 of the 75 patients included in the study, the chi-square
test showed a p-value of 0.91 (53.6% of women without dysfunction and 56.1% of
women with sexual dysfunction presented some type of rheumatic disease).
Although no statistically significant association was observed between presence
of rheumatic disease concurrent with psoriasis and the occurrence of sexual
dysfunction, the total FSFI score in women with fibromyalgia was lower (mean
15.4) than in the remaining of the psoriasis group (mean 19.6).
Discussion
The current study confirmed the impact of psoriasis on QoL, demonstrating that the
domains assessed with the SF-36 questionnaire, especially role physical, vitality,
role emotional, and mental health are worse in women with psoriasis when compared to
healthy controls. These data are consistent with previous studies in the
literature. 22 . 23 Al-Mazeedi et al.
observed the effect of psoriasis on physical activities and reported that open-air
activities and sun-bathing were affected in half of the cases, and light exercises,
such as walking, were jeopardized in 77.3% of patients. 8 The functional limitation is due mainly to pruritis,
irritation, and pain. Palmoplantar psoriasis and psoriatic arthritis add a negative
effect to QoL, since they directly affect activities of daily living. 8
According to Chiozza, psoriasis patients, more than patients with other dermatologic
diagnoses, fear social isolation and rejection and harbor fantasies of
abandonment. 24
Approximately 26% of psoriasis patients report family tensions resulting from the
disease, 50% limit their participation in sports activities, and 40% experience some
difficulty in the workplace. 25
A recent systematic literature review aimed to assess the prevalence of sexual
dysfunction in patients with psoriasis and psoriatic arthritis, analyzing such
factors as depression and extent of the disease in this relationship. 26 The review analyzed 4,039
psoriasis patients, of whom 2,567 were men (63.55%) and 1,472 were women (36.45%),
with age ranging from 23 to 62 years. In all the studies, patients were assessed as
to sexual function based on self-administered questionnaires, and some studies also
evaluated psychological aspects and QoL. Although the study populations and
questionnaires varied, sexual dysfunction was prevalent in all the studies (ranging
from 22.6% to 71.3%). 26
Later publications also addressed the subject, with prevalence of sexual dysfunction
ranging from 50% to 65%. 15 . 27 - 31 Prevalence of sexual dysfunction in our patients was high
(58.6%), statistically higher than in the control group (38.6%). This difference was
maintained in the analysis of the association between diagnosis of psoriasis and
each of the domains separately (desire, arousal, lubrication, orgasm, satisfaction,
and pain), adjusted by age, race, schooling, and marital status, showing that sexual
dysfunction is more frequent in the group of psoriasis patients in all the
domains.
Analysis of the psoriasis group showed that patients reporting sexual dysfunction
also presented more extensive skin lesions. This same relationship had been observed
by Sampogna et al. in 2007 32 , later confirmed by Guenther et al. in
2011, 33 although it is not
a consensus. 8 , 13 , 25 , 30 , 34 - 37
Various factors can impact the quality of sexual life in psoriasis patients,
including side effects of medications, increased prevalence of
comorbidities, 38 lesion
site, and symptoms of the skin condition itself, such as pruritis, psychological
alterations, and the partner's concerns 33
Comorbidities were prevalent in the psoriasis group, as reported in previous
studies. 39 , 40 Previous studies have reported a relationship
between chronic diseases, especially rheumatic comorbidities, and sexual
dysfunction. 41 , 42 However, this relationship was not
significant, although patients with fibromyalgia presented lower FSFI scores, which
is consistent with the high prevalence of sexual dysfunction described in patients
with chronic pain. 43 The absence
of statistically significant results is probably due to the small numbers in each
comorbidity, not allowing an adequate analysis of each condition.
The location of lesions also failed to show a significant association with sexual
dysfunction, consistent with the study by Van Dorssen et
al. , 44 although
differing from results reported by other authors, who pointed to genital involvement
as an important factor in quality of sexual life. 28 , 37 , 45 A possible explanation could be
that the presence of lesion has less influence than local symptoms on quality of
sexual life in these patients. Zamirska et al. assessed 93 women
for vulvar pruritis or burning sensation (mons pubis, labia majora and minora, and
clitoris). 46 They found
that 44.1% of women presented vulvar discomfort, 19.4%, pruritis, 10.8% burning
sensation, and 14% both. However, only 22 women (23.7%) presented psoriatic lesions
on the vulva, and 47.3% had a prior history of genital involvement. The authors
showed a significant correlation between vulvar discomfort and genital involvement
of psoriasis. 46
Note that prevalence of sexual dysfunction in the control group (38.6%) is slightly
higher than the values found in other studies with healthy Brazilian women, where
prevalence varied from 30% to 35.7%. 47 , 48 This could be
explained by the different epidemiological profiles of the study groups and the fact
that women with chronic diseases, except for arthritis, or chronic drug use were not
excluded.
Some limitations to the current study need to be addressed. First, although previous
diagnoses of psychiatric disorders such as depression and anxiety were an exclusion
factor, no specific psychiatric tests were applied.
Second, corroborating the literature, this group of patients with psoriasis also
showed a high comorbidity rate (64%), including diabetes mellitus and hypertension,
chronic conditions that are known to be associated with increased sexual
dysfunction. Although prior sample calculation was performed to determine the number
needed to assess the association between psoriasis and sexual dysfunction, the
calculation did not cover the determination of the possible causes of such
dysfunction. Thus, to determine the real influence of factors like emotional
alterations and comorbidities, especially rheumatic diseases, a larger sample would
probably be necessary. In addition, the complete exclusion of women with arthritis
from the control group was intended to avoid the possibility of rare cases of
psoriatic arthritis preceding cutaneous manifestation from being included
erroneously in this group. However, this made the sample intentional, which can also
be considered a bias.
Conclusions
Despite its limitations, our study was the first of its kind in female Brazilian
patients, and the results proved important to confirm the impact of psoriasis on
QoL, to identify the domains most affected, and to elucidate the relationship
between this disease and alterations in sexual function. The high prevalence of
sexual dysfunction in our patients highlights the need for a more comprehensive
approach to the health of women with psoriasis, beyond assessment of their skin
condition and the extent of the disease, including other QoL issues and specifically
sexual function.
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