INTRODUCTION
Psoriasis is a highly visible skin disease, affecting approximately
2% to 3% of the U.S. population. It causes
significant psychological and social distress and impairs
health-related quality of life (HRQOL).1-3 Psoriatic lesions are
painful, uncomfortable, and even debilitating, with significant
interference in patients' personal relationships and sexual activitiy.
4-7 The disease affects body image and self-esteem and
causes shame and embarrassment for many individuals.8,9 Large
surveys conducted in the United States and Europe have shown
that approximately 80% of patients with psoriasis feel that the
disease has a negative impact on their lives.4,10
Psoriasis can impose a substantial burden, even in those whose
disease is not extensive.11 The degree of impairment in QOL
associated with psoriasis is significant compared with U.S. population
norms and is apparent on all subscales of the Short Form
36 Health Survey (SF-36) questionnaire.2 Although the condition
in the majority of patients is not life threatening, the impairment
in the physical and mental components of QOL as measured by
the SF-36 in patients with psoriasis is comparable or even worse
than seen in patients with cancer, arthritis, heart disease, depression,
and other serious chronic medical conditions.2
Some studies have detected a correlation between disease severity
and impairment of QOL.2,4 For example, a survey of 317
patients with mild to severe disease showed that the severity
of psoriasis lesions, as rated by the self-administered Psoriasis
Area and Severity Index, was significantly correlated with the
extent of impairment in the physical and mental components
of QOL, as measured by the SF-36.2
In contrast, a study that was limited to patients with moderate
to severe plaque psoriasis showed that lesions located on visible
body parts had a significant impact on QOL, but that the
overall disease severity did not correlate with impairment in
QOL, as measured by the SF-36 instrument.12
Work limitation and productivity loss are more strongly linked
to QOL than to disease severity in patients with psoriasis.13,14 In
a study of work productivity and QOL in 201 German patients
with mild to severe psoriasis, most of whom (59%) were using
topical therapy to manage their condition, there was only a weak
correlation between the extent and severity of lesions and work
productivity.13 In contrast, there was a strong and statistically
significant correlation between impairment in QOL and reductions
in work productivity.13 Similar findings were obtained in a
study conducted in 273 patients in Sweden and Finland. Patients
who were less satisfied with their treatment tended to have more
severe disease and lower QOL; however, work productivity was
more strongly correlated with QOL than with disease severity.14