LED 308 nm phototherapy for prurigo Nodularis: A study on effectiveness, safety, and imaging-based mechanisms

INTERVENTION: LED 308nm phototherapy side:LED 308nm phototherapy;Placebo light side:Placebo light; CONDITION: Prurigo Nodularis PRIMARY OUTCOME: The Peak Pruritus‐Numerical Rating Scale (PP‐NRS) scores;The Investigator Global Assessment (IGA) scores; SECONDARY OUTCOME: Superb microvascular imaging and ultrasound elastography;The Hospital Anxiety and Depression Scale (HADS) scores;The Pain‐Numerical Rating Scale (Pain‐NRS) scores;The Dermatology Life Quality Inde X(DLQI) scores;Eosinophils count;The Sleep Disturbance‐Numerical Rating Scale (SD‐NRS) scores;Prurigo Activity Score (PAS);Acute local skin reactions, long‐term skin changes, changes in laboratory parameters, as well as all adverse events (AE) and serious adverse events (SAE).;Total IgE in the serum;Complete Blood Count; INCLUSION CRITERIA: 1.Meet the diagnostic criteria for prurigo nodularis. 2.Age >=18 years, male or female. 3.Presence of at least 10 eligible nodules on bilateral limbs (upper and/or lower extremities), with at least 5 nodules on each side, and similar severity between the two sides. 4.IGA score of 2–3, and peak pruritus NRS score >=4. 5.Disease duration >=6 weeks. 6.Poor response to prior treatment with antihistamines alone and/or topical agents, or antihistamines combined with topical agents, for 4 weeks. Note: Topical agents include glucocorticoids, calcineurin inhibitors, or vitamin D derivatives.