Delayed cutaneous hypersensitivity testing.

The topic of delayed cutaneous hypersensitivity testing is reviewed. When skin tests are used to determine whether an individual is anergic, T cell immunity is evaluated. Skin testing can be used to determine the causative organisms of infection or to discover an immunologic deficiency state. Characteristic skin lesions usually develop after intradermal injection of the antigen. Skin testing uses the most ubiquitous environmental antigens and those that are safe, cheap, and effective. Important issues dealing with skin tests include false-positive and false-negative reactions, which antigens to use in an antigen "battery," their lack of standardization, and the method of administration. Despite the problems, skin testing remains an easy, relatively safe method of assessing the immune system. Some investigators are developing more reliable testing methods and alternative antigens. Further research is needed to develop a reliable method for assessing delayed cutaneous hypersensitivity.