Topical B5 Repair Cream Combined with Desonide Cream Improves Lichen Simplex Chronicus Lesions via Inhibiting NGF: A Prospective, Self-Bilateral Controlled Trial

INTERVENTION: Treatment side (B5 repair cream group):Dexamethasone cream + B5 repair cream: Weeks 1–2: Apply dexamethasone cream once a day and B5 repair cream twice a day; Weeks 3–6: Stop using dexamethasone cream, and continue using B5 repair cream twice a day.;Control side (Vehicle moisturizer group):Dexamethasone cream + regular moisturizer: Weeks 1–2: Apply dexamethasone cream once a day and the regular moisturizer twice a day; Weeks 3–6: Stop using dexamethasone cream and continue to use the regular moisturizer twice a day.; CONDITION: Lichen Simple XChronicus (Neurodermatitis) PRIMARY OUTCOME: Lichenification score at Week 4 (bilateral comparison); SECONDARY OUTCOME: Lichenification inde Xat Week 4 (bilateral comparison);Correlation between lichenification inde Xand clinical score;NGF protein expression level at Week 6 (bilateral comparison);NRS pruritus score at Week 4 (bilateral comparison);Dermatology Life Quality Index; INCLUSION CRITERIA: 1.Aged 18 to 65 years, both genders; 2.Clinically diagnosed as lichen simple Xchronicus, based on typical lichenified lesions, severe pruritus, and chronic recurrent course; 3.One independent lesion on each corresponding bilateral body area (e.g., bilateral neck, elbows, ankles, sacrococcygeal regions, etc.), with similar severity between the two lesions and a polarized dermoscopy lichenification score difference = 1 point; 4.No use of topical corticosteroids or immunomodulators within the past 2 weeks; 5.Willing to undergo bilateral tape stripping sampling, dermoscopic image acquisition, and provide written informed consent;