An Overview of IgG4-Related Disease.

IgG4-related disease is a chronic inflammatory condition that has been formally described and extensively researched only in the recent few decades, making it a relatively new clinical entity. Furthermore, IgG4- related disease has been highly underreported and misdiagnosed as other similarly presenting conditions. In this article, we discuss the variable presentation, diagnosis process and criteria of IgG4-related disease and Sjogren's syndrome in consideration of the literature currently available. In IgG4- related disease patients, an accurate diagnosis is crucial to timely treatment and circumvention of serious adverse outcomes such as irreversible organ damage. This critical review article provides an overview of IgG4-related disease with a primary focus on (i) current understanding of its pathophysiological mechanisms, (ii) most recognized clinical phenotypes, (iii) current diagnostic guidelines, and (iv) current treatments available.