sentences:  Specialists in this field often run their own immunopathology labs.Immunodermatology testing is essential for the correct diagnosis and treatment of many diseases affecting epithelial organs including skin, mucous membranes, gastrointestinal and respiratory tracts.The various diseases often overlap in clinical and histological presentation and, although the diseases themselves are not common, may present with features of common skin disorders such as urticaria, eczema and chronic itch.Therefore, the diagnosis of an immunodermatological disease is often delayed.Tests are performed on blood and tissues that are sent to various laboratories from medical facilities and referring physicians across the United States.