Crisugabalin combined with second-generation antihistamines versus first-generation sedating antihistamines combined with second-generation antihistamines for treating chronic pruritus: a randomized controlled exploratory trial

INTERVENTION: control group:Ketotifen 1mg QN combined with a second‐generation non‐sedating antihistamine;experimental group:Crisugabalin 20mg BID combined with a second‐generation non‐sedating antihistamine; CONDITION: Prurigo nodularis, Chronic pruritus of unknown origin PRIMARY OUTCOME: Change in the Worst Itch Numeric Rating Scale (WI‐NRS) weekly average from baseline at Week 4; SECONDARY OUTCOME: Frequency, severity, and relationship to study drug of adverse events (AEs) and serious adverse events (SAEs) from baseline to week 5;Absolute and percentage changes from baseline in the Worst Itch Numeric Rating Scale (WI‐NRS) score;Percentage of subjects with Patient Global Impression of Change (PGIC) scores of "very much improved" or "much improved" at weeks 2 and 4;Changes in Dermatology Life Quality Inde X(DLQI) scores from baseline at weeks 2 and 4;Change in Generalized Anxiety Disorder‐7 (GAD‐7) scores from baseline at weeks 2 and 4;Change in pain numerical rating scale score from baseline at weeks 2 and 4, representing the most severe pain.;Proportion of subjects with a >= 4‐point reduction in the Worst Itch Numeric Rating Scale (WI‐NRS) score;Changes in Patient Health Questionnaire‐9 items (PHQ‐9) scores from baseline at weeks 2 and 4;Changes in 5D Itch Scale scores from baseline at weeks 2 and 4;Changes in Pittsburgh Sleep Quality Inde X(PSQI) scores from baseline at weeks 2 and 4;Change in the Worst Itch Numeric Rating Scale (WI‐NRS) weekly average from baseline at Week 2; INCLUSION CRITERIA: 1.Aged 18‐65 years, gender not limited. 2.Clinically diagnosed with PN or CPUO by a dermatology specialist, and itching has persisted for at least 6 weeks. 3.Currently receiving and have been stably using any of the following second‐generation non‐sedating antihistamines for at least 2 weeks: ebastine 10mg qd, loratadine 10mg qd, or cetirizine 10mg qd. 4.Despite the above treatment, itch control is still not ideal, defined as: a WI‐NRS average score of =4 points in the past week at the baseline visit, and both the patient and the investigator believe that more intensive treatment is necessary. 5.Agree to maintain the same type and dosage of background antihistamine medication during the study. 6.Female subjects of childbearing potential (WOCBP) and male subjects who have not undergone vasectomy agree to use reliable methods of contraception during the trial, including for 6 months after the end of the study or discontinuation of treatment [abstin