Primary Cutaneous Amyloidosis

This trial is planned to investigate the efficacy and safety of Stapokibart (an IL-4 receptor antagonist) in patients with PCA.

The aim of this clinical trial is to find out whether the combination of tocilizumab tablets and acitretin capsules is more effective than acitretin capsules alone in treating primary cutaneous amyloidosis. It will also investigate the safety of the combination of tocilizumab tablets and acitretin capsules. The main questions it aims to answer are: 1. Does the combination of tocilizumab tablets and acitretin capsules relieve the pruritus symptoms of the participants faster and reduce the pruritus score more than acitretin capsules alone? 2. What medical problems will the participants encounter when taking tocilizumab tablets combined with acitretin capsules? The researchers compared the combination of tocilizumab tablets and acitretin capsules with acitretin capsules alone to see if the combination could better treat primary cutaneous amyloidosis without causing serious adverse reactions. Participants will: 1. Take the combination of tocilizumab tablets and acitretin capsules or acitretin capsules alone every day for 16 weeks. 2. Visit the clinic once every 4 weeks for checkups and tests. 3. Observe participants at 4 weeks, 12 weeks and 24 weeks after discontinuation of medication to determine the recurrence status. 4. Collect the visual analogue scale (VAS) scores for pruritus, symptom severity (SCORAD) scores , rash area and severity, treatment response (EASI) scores, dermatological quality of life index (DLQI), and insomnia severity index (ISI) of participants before and after treatment.