Systematic review and meta-analysis of treatments and outcomes in primary localized cutaneous amyloidosis

Background Primary localized cutaneous amyloidosis (PLCA) is a skin-limited disorder characterized histologically by amyloid deposition in the papillary dermis.Objectives To review current treatment strategies and provide an updated perspective on the treatment of PLCA.Methods We searched the PubMed, EMBASE and Cochrane Library databases for eligible studies. Studies were divided into those that described nodular amyloidosis (NA) and those that described non-NA. Cohort studies were meta-analysed using a random effects model to evaluate the outcomes of different treatments, while case reports and case series were evaluated using the Mann-Whitney U-test.Results Overall, 116 studies involving 534 patients were included. Surgery was the most effective treatment option in patients with NA, with statistically significantly better outcomes compared with other treatments. For the non-NA group, 62 case-level studies (79 patients) and 20 cohort studies (418 patients) were analysed separately. Although there were no statistically significant differences between treatments in the case-level studies, biologic agents and Janus kinase (JAK) inhibitors may be promising treatments for refractory lesions. Among the cohort studies, partial response rates of 100.0%, 100.0%, 97.5%, 96.9% and 94.4% were achieved for transcutaneous electrical nerve stimulation, microneedling, laser therapies, topical therapies and systemic immunosuppressants, respectively; complete response rates of 22.2% and 2.5% were achieved for surgical interventions and laser therapies, respectively.Conclusions This study suggests that surgery is the most effective treatment option for NA, and laser therapy is recommended for patients with non-NA. Biologic agents and JAK inhibitors may be promising treatment options for lesions that do not respond to conventional therapies. This study aimed to review current treatment strategies and provide an updated perspective on the treatment of primary localized cutaneous amyloidosis. Our findings suggest that surgery is the most effective treatment option for nodular amyloidosis, while laser therapy is recommended for patients with non-nodular amyloidosis. Biologic agents and Janus kinase inhibitors may be promising treatment options for lesions that do not respond to conventional therapies.