Psoriasis is a chronic inflammatory skin disorder of unknown etiology, although it is thought to be caused by the interaction of multiple genes, the immune system, and certain environmental factors.1 It affects approximately 2% of the world's population, with a similar prevalence in men and women.2 In Spain the estimated prevalence in the general population is between 1.17% and 1.43%, with onset usually occurring in individuals aged between 20 and 50 years.3

Psoriasis has a considerable impact on patients’ lives and affects physical health, psychological state, social relationships, and work.4,5 The disorder is frequently associated with a range of comorbidities, including inflammatory bowel disease, heart disease, and obesity, thus complicating management and negatively impacting mental and emotional health.6 Psoriasis has been reported to have a similar or even greater effect on quality of life than other chronic diseases such as ischemic heart disease or diabetes mellitus.7–9 Quality of life in psoriasis has been reported to be directly related to disease severity7,10 and appears to be influenced, to varying degrees, by a wide range of physical and psychosocial factors.7,9

Given the chronic nature of psoriasis, patients often require long-term treatment, which varies according to multiple factors such as the extent and severity of disease and the presence of psoriatic arthritis or other comorbidities.11 Conventional treatment can be very effective in the short term, but cumulative toxicity is often a problem in the long-term management of psoriasis.12 New biologic agents that act more selectively on key inflammatory components are now considered a therapeutic alternative in this disorder.13

In view of the scant information available on the management of psoriasis in routine clinical practice in Spain, we designed a study to describe the clinical characteristics and treatment of patients with moderate to severe psoriasis in Spain and to assess the impact of the disease on their quality of life.

We performed a multicenter, epidemiological, observational, cross-sectional study in which the investigators were dermatology specialists treating patients with psoriasis at hospitals, specialist centers, or private offices. The patients were enrolled consecutively during scheduled visits. All the data required for the study were collected during a single visit, which coincided with enrolment.

The inclusion criteria were an age of 18 years or older and a diagnosis of moderate or severe psoriasis, defined as a Psoriasis Area and Severity Index (PASI) score of 10 or higher and/or a body surface area affected by psoriasis (BSA) of 10% or more. Those enrolled were also required to have started treatment with systemic drugs, phototherapy, and/or topical treatment between 2004 and 2006. Written informed consent was obtained from all patients prior to inclusion and confidentiality of data was guaranteed. The study was approved by the clinical research ethics committee at Hospital Nuestra Señora de Sonsoles in Ávila. Patients were recruited from 90 centers between March and November, 2009. Following enrolment at a scheduled visit, each patient was interviewed and his or her medical record reviewed, with collection of sociodemographic and clinical data, including general clinical information, clinical characteristics specific to psoriasis, and information regarding treatment. Disease severity was also assessed (BSA or PASI) at this visit, as was quality of life using the patient-assessed Dermatology Life Quality Index (DLQI).14 A score of 5 or less on the DLQI was considered to indicate good or satisfactory quality of life while one of 6 or higher was considered to indicate poor or unsatisfactory quality of life.

The findings of the present study highlight the considerable impact that psoriasis has on patient quality of life, the importance of determining disease severity before initiating treatment, and the need for a multidimensional approach to management, as has been mentioned by other authors.15 All the patients in our study had moderate to severe plaque psoriasis, diagnosed according to clinical criteria based on BSA and PASI scores, and they had all started specific psoriasis treatment with systemic agents, phototherapy, and/or topical drugs between 2004 and 2006. The characteristics of our patients are similar to those described in other epidemiological studies of moderate to severe plaque psoriasis in Europe.15–17 In our series, most of the patients had moderate disease (76.2%), there was a predominance of male patients (62.2%), and the mean duration of disease was 13 years. As was to be expected, there was a high prevalence of concomitant disease, and 17.5% of the patients had associated arthritic psoriasis.

Severe psoriasis (present in 23.8% [n=105] of our patients) was significantly associated with longer disease duration and a higher prevalence of concomitant disease, nail alterations, and lesions with marked scaling. The areas most significantly affected were the scalp, flexures, palms and soles, and the genital area. While psoriatic arthritis appears to be more common in patients with more extensive disease,18 it can also run an aggressive course in patients with less severe psoriasis.19 Like other authors,17,20 we did not detect any differences in the prevalence of psoriatic arthritis according to disease severity. We also did not observe any significant differences in the prevalence of severe disease in men compared to women or detect a relationship with smoking, contrasting with reports from an earlier epidemiological study published in Spain.17

Psoriasis is significantly associated with a variety of physical and psychological dimensions that affect patient quality of life, hence the consideration that dermatologists need to manage this disorder from a multidimensional approach.7,9,10,20,21 A recent study of psoriasis patients in hospital and outpatients settings in Spain reported that the disease had a considerable impact on quality of life, particularly with regard to emotional status.21 In our study, 60% of patients with severe psoriasis but just 39.8% of those with moderate disease had a poor or unsatisfactory quality of life; furthermore, in those with severe disease, all 6 domains of the DLQI were significantly affected. Regardless of disease severity, we observed a significant association between poor quality of life and the presence of concomitant psychiatric conditions and greater scalp involvement. Age, by contrast, was a protective factor. Psychiatric morbidity was the strongest predictor of poor quality of life in our patients, with an OR of 5.105, contrasting with PASI score, which was the weakest predictor, with an OR of 1.067. This finding is consistent with those of previous studies.7,15 Our findings with regard to age are consistent with those reported in a systemic review of quality of life in psoriasis in that higher age was correlated with a better quality of life.7 In agreement with other reports,20 we did not detect significant differences in quality of life between patients with psoriasis and psoriatic arthritis and those with psoriasis alone.

In an epidemiological study of severe psoriasis in Spain and Portugal conducted between 2004 and 2005, approximately only half of the patients surveyed were receiving conventional systemic treatment.17 The authors, like others,15 concluded that psoriasis was inadequately treated in many of these patients. One of the most relevant aspects of the present study is that we analyzed the prescribing habits of Spanish dermatologists in a retrospective analysis of up to 5 years (2004-2009). During this period, 68% of the patients in our series had been treated with conventional systemic agents, 39.1% with biologic therapy, 22.3% with phototherapy, and 64.1% with concomitant topical drugs. The mean duration of treatment was approximately 2 years for topical treatment, approximately a year and a half for conventional systemic agents and the first biologic agent received, and less than a year for phototherapy. Although all the patients in our study had moderate to severe psoriasis, just 39.1% had received biologics during this period; this is probably related to the gradual introduction of biologic drugs starting in 2005, which is when efalizumab, infliximab, and etanercept were marketed for the first time. When enrolled in the study in 2009, 57.5% of the patients were on biologic agents, indicating an increasing tendency to use these drugs in moderate to severe psoriasis. Nevertheless, considering the centers that were selected to participate in the study, it should be noted that this figure may possibly be higher than the average for Spain.

Despite the availability of international guidelines on the treatment of psoriasis,22,23 which include recommendations on the use of conventional systemic agents, and despite the fact that these drugs have known beneficial effects, questions remain about the optimal use of these drugs.11,15 Current guidelines, for example, do not recommend how long systemic drugs should be ideally administered before switching to biologics in those cases where it is necessary. In our series, the mean duration of treatment, including conventional systemic treatment and phototherapy, before a switch to the first biologic agent, was over 2 years, providing new data on the therapeutic management of psoriasis in Spanish clinics. New guidelines with recommendations on how long patients should receive systemic treatment before switching to biologic agents would certainly help to improve the management of psoriasis.

When interpreting the findings of the present study and extrapolating them to a national level or drawing comparisons with populations with similar characteristics, it is important to note that certain biases may have been introduced, mostly related to the retrospective design of the study and the selection of participating centers. Nonetheless, the observational nature of the study is its main strength as it allowed us to provide a descriptive analysis of the clinical characteristics and treatment profile of patients with moderate to severe psoriasis in routine clinical practice in Spain.

To conclude, based on our findings, severe psoriasis is significantly associated with longer disease duration; a higher prevalence of comorbidity, nail alterations, and lesions with marked scaling; greater involvement of the scalp, flexures, palms and soles, and genital area; and considerably impaired quality of life. The strongest predictor of poor or unsatisfactory quality of life was the presence of psychiatric comorbidity, regardless of disease severity. The mean duration of treatment, including conventional systemic treatment and phototherapy, before switching to the first biologic agent, was over 2 years.

Dr José Manuel Hernánz, Dr Manuel Sánchez-Regaña, and Dr Rosa Izu participated in clinical trials sponsored by Pfizer Spain and received consultancy and speakers’ fees for activities sponsored by Pfizer Spain.

Dr Victoria Mendiola has participated in clinical trials sponsored by Pfizer Spain.

Dr Carmen García-Calvo works in the Medical Department of Pfizer, S.L.

This study was financed by Pfizer Spain. The authors did not receive fees for contributing to the writing or publication of this manuscript.

Publishing support was provided by UBC Scientific Solutions and financed by Pfizer Spain.