BACKGROUND Autosomal recessive congenital ichthyosis (ARCI) and ichthyosis syndrome (IS) are rare genetic skin disorders. OBJECTIVE To estimate the number of patients with ARCI and IS in Japan and clarify the clinicoepidemiologic features of these diseases. METHODS We performed a nationwide survey of patients treated for ARCI or IS during January 2005-December 2009. We developed diagnostic criteria and conducted a primary survey in a stratified random sample of Japanese hospitals to quantify the number of outpatients and inpatients with ARCI or IS. We performed a secondary survey of clinicoepidemiologic features in positive cases. RESULTS The estimated number of patients receiving treatment for ARCI and IS during 2005-2009 was 220 (95% confidence interval [CI] 180-260). The estimated disease distribution was as follows: 95 (95% CI 80-110) patients with nonbullous congenital ichthyosiform erythroderma, 30 (95% CI 20-40) with lamellar ichthyosis, 15 (95% CI 10-20) with harlequin ichthyosis, and 85 (95% CI 50-120) with IS. LIMITATIONS Patients with a mild case of the disease might not have visited a dermatology department, potentially causing underestimation of affected patients. CONCLUSION We report the estimated number of patients with ARCI and IS in Japan and sex differences in the age distribution.

中文翻译：

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日本对常染色体隐性先天性鱼鳞病和鱼鳞病综合征进行全国流行病学调查的结果。

背景技术常染色体隐性遗传性先天性鱼鳞病（ARCI）和鱼鳞病综合征（IS）是罕见的遗传性皮肤疾病。目的估算日本ARCI和IS患者的数量，并阐明这些疾病的临床流行病学特征。方法我们在2005年1月至2009年12月期间对接受ARCI或IS治疗的患者进行了全国性调查。我们制定了诊断标准，并在日本医院的分层随机样本中进行了初步调查，以量化ARCI或IS的门诊患者和住院患者的数量。我们对阳性病例的临床流行病学特征进行了二次调查。结果2005-2009年间接受ARCI和IS治疗的患者估计数为220（95％置信区间[CI] 180-260）。估计的疾病分布如下：95例（95％CI 80-110）非先天性鱼鳞状红皮病，30例（95％CI 20-40）患有板状鱼鳞病，15例（95％CI 10-20）患有丑角鱼鳞病和85例（95％CI 50- 120）与IS。局限性病情较轻的患者可能没有去皮肤科就诊，有可能导致低估患病患者的人数。结论我们报告了日本ARCI和IS患者的估计人数以及年龄分布的性别差异。