Different clinical features of pediatric generalized pustular psoriasis in patients with or without IL36RN variants

Abstract
Background: Generalized pustular psoriasis (GPP) is a rare and life-threatening autoinflammatory dermatological disease. IL36RN was reported to be the main pathogenetic basis for GPP. Only a few studies have reported on the correlation analysis of IL36RN variants and the phenotype of pediatric-onset GPP (PGPP). 
Methods: IL36RN was screened in 60 children diagnosed with GPP from January 2013 to January 2020, and their detailed clinical profiles were obtained. 
Results: Forty-six out of 60 (76.67%) patients harbored IL36RN variants, and six IL36RN variants were found, of which two were novel variants that were reported for the first time. The frequency of IL36RN variants was significantly different among the subtypes of GPP [GPP with acrodermatitis continua of Hallopeau (ACH) group, 100%; GPP without plaque psoriasis (PV) and ACH, 78.05%; GPP with PV group, 44.44%](P=0.018), while the percentage of IL36RN variants in the GPP with ACH group was higher than that in the GPP WITH PV group (P0.05). IL36RN variants were associated with a lower percentage of PV, longer length of hospitalization, and longer time to reach normal body temperature after treatment (P0.05). After treatment, marked responses, moderate responses, and no responses were recorded in 75.00%, 8.33%, and 16.67% of patients, respectively. No significant difference was observed during efficacy assessment in patients with or without IL36RN variants (2=1.122, P0.05). 
Conclusions: IL36RN variants are associated with GPP with ACH subtypes, an absence of concurrent PV, and a greater extent of severe inflammation. Acitretin was an effective treatment for patients in our study and mostly resulted in a marked response in our cohort.