Fulminant type 1 diabetes mellitus in Japanese children and adolescents: multi-institutional joint research of the Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes.

Fulminant type 1 diabetes mellitus (FT1DM) is a subtype of type 1 diabetes mellitus characterized by a remarkably abrupt onset. In Japan, FT1DM accounts for approximately 20% of acute-onset adult type 1 diabetes mellitus cases; however, reports of pediatric-onset FT1DM are rare. We aimed to determine the frequency and clinical characteristics of FT1DM in Japanese children and adolescents by conducting a 2-phase questionnaire survey among the members of the Japanese Study Group of Insulin Therapy for Childhood and Adolescent Diabetes (JSGIT) regarding their clinical experience with FT1DM. Responses were obtained from 54 of the 79 participating hospitals (68.4%). Of these, 8 hospitals managed a total of 15 pediatric patients with FT1DM (4 patients in each of 2 hospitals, 2 patients in 1 hospital, and 1 patient in each of 5 hospitals). The distribution of patient age was biphasic, with peaks in children younger than 5 years and older than 8 years of age. The clinical characteristics of FT1DM in this population (such as the duration from onset of symptoms to diagnosis, severity of symptoms, preceding flu-like episodes, and abnormal laboratory data) did not differ from those of patients with adult-onset FT1DM. The frequency of pediatric-onset FT1DM is low compared with that of adult-onset FT1DM. The genetic background and susceptibility patterns of pediatric patients with FT1DM may differ from those typical of adults with FT1DM, but both age groups share similar clinical characteristics.