Toxicant-induced Loss of Tolerance

Toxicant-induced Loss of Tolerance is a two-stage disease process:

(1) Initiation.

An initial chemical exposure, either chronic low-level, such as a sick building, or an acute exposure such as to pesticides, causes a fundamental breakdown in natural tolerance, leading to newly-acquired intolerances.

(2) Triggering.

Subsequently, previously tolerated substances including everyday chemical exposures, foods, medications, alcoholic beverages, and caffeine trigger multi-system symptoms.

Masking greatly complicates identification and treatment of TILT. Everyday we are exposed to many different foods, chemicals, drugs, etc…. Patients with TILT typically develop intolerances to dozens of different exposures (called “incitants” – chemicals that trigger a response). Masking is the hiding of a response to a particular exposure by a patient’s responses to the many other exposures (chemicals, foods, drugs) that now trigger symptoms as a result of TILT. This overlapping of exposures and responses in time requires a structured effort to minimize exposures to potential incitants so as to reduce the background “noise” that makes it hard link causes and effects between exposures and symptoms. Getting the patient to a clean baseline is a key step in effectively investigating TILT.

References

Toxicant-induced Loss of Tolerance-An emerging theory of disease?
Miller CS. Environ Health Perspect 1997 Mar;105 S:445-453.

Empirical approaches for the investigation of toxicant-induced loss of tolerance
Miller CS, Ashford NA, Doty R, Lamielle M, Otto D, Rahill A, Wallace L. Environmental Health Perspectives 1997 Mar;105(2):515-519.