At present, there is no diagnostic test to easily and quickly identify environmental sensitivities. If a physician suspects an environmental factor is the cause of a patient’s health problem, the physician usually looks closely at the medical history and exposure, does a complete physical exam and pres- cribes routine laboratory tests.
Six diagnostic criteria have been identified for environmental sensitivities:
- Symptoms are reproducible with repeated exposure (meaning that symp- toms appear each time the person is exposed to a specific trigger)
- The condition is chronic
- Symptoms manifest themselves at low levels of exposures (lower than previously tolerated by the patient or commonly tolerated by the rest of the population)
- Symptoms improve or resolve when exposure ceases
- The patient reacts to multiple chemically unrelated substances
- Symptoms involve multiple organ systems
To these six criteria, researchers have added four symptoms clinically observed in patients:
- Having a stronger than average sense of smell
- Having difficulty concentrating
- Feeling “spacey”
- Feeling dull, gloomy or foggy
Although the last two seem vague and are difficult to measure, they are quite real to the people who ex- perience them. These symptoms are especially useful to establish a diagnosis of chemical sensitivities.
In Search of a diagnostic test
In some cases, a diagnosis of environmental sensitivities to chemical products can be based on chemi- cal analyses of patients’ blood, urine, hair or tissue to determine the levels of toxic substances present. Biomarker discovery, (e.g. an abnormally high or low level of a substance in the blood linked with the metabolism of a toxic invader) or the presence of a genetic marker is the most promising approach to diagnose environmental sensitivities.