Itch in Psoriasis: A New Look at Well-known Subject

Psoriasis is a chronic inflammatory dermatosis, frequently presenting with chronic itch. This study investigated the prevalence and detailed clinical characteristics of chronic itch in 143 psoriatic patients, with regard to different age groups, comorbidities and pharmacotherapy. Chronic itch was reported by 72% of subjects. Patients aged 65 years and over presented higher 4-Item Itch Questionnaire (4IIQ) scores (8.6 +/- 3.4 vs. 7.4 +/- 2.5 points; p = 0.03) and rarely experienced itching at midday (p = 0.009). Chronic itch correlated with aspirin intake and xerosis intensity. 4IIQ scores were higher in patients with asthma/chronic obstructive pulmonary disease, peptic ulcer disease and those taking insulin. Logistic regression analysis found that chronic itch was positively correlated with the use of antacids, angiotensin receptor blockers, angiotensin enzyme converting inhibitors, beta-blockers, xerosis intensity and Physician's Global Assessment score, whereas psychiatric drugs other than selective serotonin reuptake inhibitors, allopurinol, coexistence of arterial hypertension and application of emollients acted conversely. Elderly psoriatic patients present several differences in the characteristics of chronic itch, and chronic itch may be associated with comorbidities and pharmacotherapy. To the best of our knowledge, this is the first study to report possible associations between psoriatic pruritus and co-administration of drugs utilized in various systemic conditions.