Reliability and validity of internalized stigmatization scale in psoriasis

Background and Design: Internalized stigma involves endorsing negative feelings and beliefs, such as insignificance, shame and withdrawal triggered by applying these negative stereotypes to oneself. The Internalized Stigma Scale has not been applied to psoriasis patients. We aimed to evaluate the reliability and validity of the Internalized Stigma Scale in psoriasis patients. Materials and Methods: 100 consecutive, volunteer psoriasis patients (48 female, 52 male; aged, 40.59 +/- 15.44 years) were enrolled in the study. Psoriasis area and severity index (PASI) and body surface area (BSA) were evaluated by a physician (A.B.T.). The patients responded contemporaneously to Psoriasis Internalized Stigma Scale (PISS), Dermatology Quality of Life Index (DQoL), and the Perceived Health Status (PHS), single-item self-rated general health questionnaire, of which Likert scores 1, 2, and 3 were classified as "from fair to very poor", and 4, 5 as "good". Results: Cronbach's alpha coefficient of the PISS subscales was 0.83 for alienation, 0.70 for stereotype endorsement, 0.70 for perceived discrimination, 0.84 for social withdrawal, and 0.68 for stigma resistance. The same value was 0.89 for the total scale. Mean PISS and DQoL scores were 58.8 +/- 12.6 and 10.0 +/- 9.4, respectively. The PISS was significantly correlated with the patients' DQoL scores (r=0.726, p=0.001). The PISS was also significantly correlated with disease duration (r=0.209, p=0.047). There was no significant relationship between PISS and PASI or BSA. Mean DQoL scores in patients reporting their PHS as "from fair to very poor" and "good" were 12.1 +/- 7.3 and 5.0 +/- 4.3, respectively. Mean values of PISS in patients reporting their PHS as "from fair to very poor" was significantly increased compared with patients reporting their PHS as "good" (p=0.001). Conclusion: The PISS can be used as a reliable and valid tool in assessing internalized stigmatization in psoriasis patients. Our results indicate a high level of stigmatization in psoriasis patients. Low DQoL scores show a correlation with increased levels of internalized stigmatization. PHS is also worse in patients with low DQoL scores.