Epidemiology and clinical characteristics of bullous congenital ichthyosiform erythroderma (keratinolytic ichthyosis) in Japan: Results from a nationwide survey

BackgroundDetailed nationwide surveys of the epidemiologic and clinical characteristics of bullous congenital ichthyosiform erythroderma (BCIE) (novel synonym: keratinolytic ichthyosis) in a large population have not been performed previously to our knowledge.ObjectiveWe sought to estimate the number of patients with BCIE who visited dermatology departments in Japan in 2002 and to clarify the clinical and epidemiologic features of the disease.MethodsA nationwide mail survey was sent to dermatology departments and consisted of an initial survey to estimate the number of individuals with BCIE and a second survey to obtain data on the clinical characteristics of these patients.ResultsThe total number of patients with BCIE in Japan was estimated to be 55 (95% confidence interval, 35-75). Clinical data were able to be collected from 28 cases. Clinical manifestations included rash in 27 cases (96.4%), erythroderma in 19 cases (67.9%), and generalized blistering in 15 cases (57.7%). Approximately 75% of patients younger than 20 years showed generalized blistering. Hystrixlike scales were present in 8 female patients (57.1%), whereas large scales were present in 8 male patients (57.1%). Among the 19 patients for whom histopathological information was available, 17 (89.5%) showed granular degeneration.LimitationsPatients with BCIE who have few subjective symptoms may not have visited a dermatology department, potentially resulting in an underestimation of the number of patients with BCIE.ConclusionImportant epidemiologic and clinical information on characteristics of BCIE in Japan was obtained, including an estimate of the total number of patients with BCIE in Japan.