SAN ANTONIO (July 10, 2012) -- Chemical intolerance contributes to the illnesses of 1 in 5 patients but the condition seldom figures in their diagnosis, according to clinical research directed by a UT Medicine San Antonio physician.
Clinical tools are available to identify chemical intolerance but health care practitioners may not be using them, lead author David Katerndahl, M.D., M.A., said. The study is in the July 9 issue of Annals of Family Medicine. UT Medicine is the clinical practice of the School of Medicine at The University of Texas Health Science Center San Antonio.
Avoidance of triggers
The study's authors said physicians need to know how chemical intolerance affects certain people and understand that conventional therapies can be ineffective. Some patients would improve by avoiding certain chemicals, foods and even medical prescriptions, the authors said.
Patients with chemical intolerance go to the doctor more than others, are prone to having multi-system symptoms and are more apt to have to quit their job due to physical impairment, the authors said.
The study involved 400 patients who gave personal health information while waiting to be seen at primary care clinics in San Antonio, one in UT Medicine and the other in the University Health System. The researchers asked the patients to respond to 90 questions about their illnesses, mental health and ability to function.
In the end, the authors said, 20.3 percent of the patients questioned met the scientific criteria for chemical intolerance.
Researchers surveyed patients with chronic conditions such as allergies, asthma, diabetes and heart disease. They excluded patients who were at the clinics for acute conditions such as earaches, flu or bone fractures.
The origins of chemical intolerance have been the subject of much speculation, the authors acknowledge, but the condition is also understudied. People with chemical intolerance, or "CI," are highly sensitive to common substances such as cleaning products, tobacco smoke, fragrances, pesticides, new carpet and auto exhaust.
Important consideration in care
"Apart from the debate over causality, the fact that so many patients meet the criteria for chemical intolerance holds particular relevance for primary care providers," said Dr. Katerndahl, professor of family and community medicine who is supported by the Dr. Mario E. Ramirez Distinguished Professorship.
Chemically intolerant individuals often have symptoms that affect multiple organ systems simultaneously, especially the nervous system. Symptoms commonly include fatigue, changes in mood, difficulty thinking and digestive problems.
Study co-authors from the School of Medicine at the UT Health Science Center include Claudia S. Miller, M.D., M.S., professor in environmental and occupational medicine, vice chair of family and community medicine, and director of the South Texas Environmental Education and Research (STEER) Program, among her roles, and Raymond F. Palmer, Ph.D., M.A., associate professor of family and community medicine.
Study co-author Iris R. Bell, M.D., Ph.D., is professor emeritus of the Department of Family and Community Medicine at the University of Arizona College of Medicine and research professor in the College of Nursing at the University of Arizona.
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About UT Medicine San Antonio
UT Medicine San Antonio is the clinical practice of the School of Medicine at the UT Health Science Center at San Antonio. With more than 700 doctors - all faculty members from the School of Medicine - UT Medicine is the largest medical practice in Central and South Texas. Expertise is in more than 100 different medical specialties and subspecialties. Primary care doctors and specialists see patients in private practice at UT Medicine's clinical home, the Medical Arts & Research Center (MARC), located in the South Texas Medical Center at 8300 Floyd Curl Drive, San Antonio 78229. Most major health plans are accepted, and there are clinics and physicians at several local and regional hospitals, including CHRISTUS Santa Rosa, University Hospital and Baptist Medical Center. Call (210) 450-9000 to schedule an appointment, or visit the website at www.UTMedicine.org for a complete listing of clinics and phone numbers.