Developmental immunotoxicity (DIT): the why, when, and how of DIT testing.

Developmental immunotoxicity (DIT) has emerged as a serious health consideration given the increases in the prevalence of many immune-based childhood diseases and conditions, including allergic diseases and asthma, recurrent otitis media, pediatric celiac disease, and type 1 diabetes. As a result, the use of DIT testing to identify potential environmental risk factors contributing to these and other diseases has become a higher priority. This introductory chapter considers: (1) the basis for an increased and earlier use of DIT testing in safety evaluations and (2) the general features of DIT testing strategies designed to reduce health risks.