gms | German Medical Science

Background: Psoriasis is a chronic inflammatory skin disease affecting 2–4% of the population. While stress plays a paramount role on its onset/exacerbation, via over-activation of the hypothalamic-pituitary-adrenal axis and consequent release of pro-inflammatory cytokines, the cutaneous inflammatory response induces anxiety/depression, via body disfigurement and stigmatization. The severity of pruritus and the involvement of anogenital areas have been described as additional risk factors for psychological comorbidity.

Objectives:

1.

to examine the main and interaction effects of severity of pruritus and anogenital involvement on patient-reported outcomes (PRO) of disease burden and psychological comorbidity;

2.

to identify the sociodemographic, clinical and PRO variables associated with clinically significant symptoms of depression/anxiety.

Methods: Cross-sectional observational study including German patients aged ≥ 18 years with psoriasis vulgaris. Disease severity was assessed with PASI and severity of pruritus with a 0 to 10 numeric rating scale (NRS). PRO of disease burden included the Dermatology Life Quality Index (DLQI), Itchy-QoL, Patient Benefit Index (PBI), Dysmorphic Concern Questionnaire (DCQ), Perceived Stigmatization Questionnaire (PSQ) and Relationship and Sexuality Scale (RSS). Psychological morbidity was assessed with the Patient Health Questionnaire (PHQ-2) and the Generalized Anxiety Disorder (GAD-2), using cut-off scores ≥ 3 as indicators of clinically significant symptoms of depression/anxiety.

Results: The participants were 107 patients with psoriasis (mean age=46.3 ± 14.6; 53.3% male), of which 43 reported moderate/severe pruritus (NRS ≥ 4) and 31 presented lesions in the anogenital area. Analyses of covariance showed that patients with moderate/severe pruritus reported more QoL impairments (DLQI: F=21.46, p < 0.01; Itchy-QoL: F=32.93, p < 0 .01), anxiety symptoms (F=5.60, p=0.02), and dysmorphic concerns (F=6.08, p=0.02), but less treatment benefits (F=12.65, p < 0.01), than those with no/mild pruritus. No main effects of anogenital involvement were found, but its interaction effects with pruritus were significant for depression symptoms (F=4.20, p=0.04) and stigmatization (F=3.96, p=0.05), with a stronger detrimental effect of moderate/severe pruritus for patients without anogenital involvement. Univariate logistic regressions identified several sociodemographic (e.g., gender), clinical (e.g., severity of pruritus, sleeping problems) and PROs (e.g., dysmorphic concerns, stigmatization) predicting the likelihood of clinically significant symptoms of depression/anxiety; however, only the PBI remained significant in multivariate regression.

Discussion: Pruritus induces significant burden and psychological morbidity, particularly for patients without anogenital involvement. The coping strategies used by patients with anogenital psoriasis (e.g., social avoidance) should be thoroughly evaluated as these can be highly dysfunctional for overall psychosocial adaptation.

Practical implications: Patient-centered healthcare that considers patient-defined needs/benefits might be the best way to prevent anxiety and depression disorders.