Japanese guidelines for diagnosis and treatment of urticaria in comparison with other countries.

Several guidelines for urticaria and angioedema have been published in Europe and United States since 1997. General principles for diagnosis and treatments of them are similar. However, each guideline has its own characteristics and shows differences in areas such as the coverage of urticaria subtypes, nomenclatures, and hierarchy of the medications. In Japan, the Japanese Dermatological Association (JDA) published its first guideline for urticaria and angioedema in 2005. It established a new classification of urticaria and angioedema together with the definition of each subtype. It emphasized the importance of discriminating idiopathic urticaria, consisting of acute urticaria and chronic urticaria from inducible urticaria, such as allergic urticaria, physical urticaria and cholinergic urticaria. It contains several unique algorithms for diagnosis and treatment of urticaria from a view point of clinical practices, and was further enforced by a style of EBM in 2011. Nevertheless, these guidelines have not been recognized outside of Japan, because of a language barrier. In this article, the outline of the newest guidelines by JDA are introduced and compared with the guidelines in other countries published in English.