Relationship Between Family History and Quality of Life in Patients with Psoriasis: A Cross-Sectional Study from China.

PURPOSE: The purpose of this study was to investigate the comprehensive impact of family history of psoriasis, lesion size, disease severity, and the possibility of joint involvement on patients' quality of life(QoL).

PATIENTS AND METHODS: Data from 5961 patients with psoriasis recruited from 440 hospitals throughout China were analyzed. The effects of family history of psoriasis, Body Surface Area(BSA), Psoriasis Area and Severity Index(PASI), and Psoriasis Epidemiology Screening Tool(PEST) on their Dermatology Life Quality Index(DLQI) were studied using a moderated chained mediated effects test.

RESULTS: A total of 912 patients (15.30%) had a family history of psoriasis, and 5071 patients (85.10%) had plaque psoriasis. In patients with plaque psoriasis, the variables of family history, PASI, PEST, and DLQI were positively correlated with each other. Additionally, in patients with other types of psoriasis, PASI was positively correlated with PEST and DLQI. Age was positively correlated with PASI and PEST and negatively correlated with DLQI in patients with plaque psoriasis; their Body Mass Index(BMI) and disease duration were in positive correlation with PASI and PEST. The mediation effect of PASI and PEST between family history and DLQI was remarkable in patients with plaque psoriasis and not in those with other types of psoriasis. BSA moderated the association between family history and PASI in patients with plaque psoriasis.

CONCLUSION: PASI and PEST play a chain mediating role in the relationship between family history and DLQI in patients with plaque psoriasis, and high levels of BSA increase the ability of family history to positively predict PASI in plaque psoriasis, thereby affecting the patient's QoL.