COMPARISON OF PATIENTS WITH CHRONIC FATIGUE SYNDROME, FIBROMYALGIA, AND MULTIPLE CHEMICAL SENSITIVITIES

Background: Chronic fatigue syndrome (CFS), fibromyalgia (FM), and mul tiple chemical sensitivities (MCS) are conditions associated with fati gue and a variety of other symptoms that appear to share many clinical and demographic features. Our objectives were to describe the similar ities and differences among patients with CFS, FM, and MCS. Additional objectives were to determine how frequently patients with MCS and FM met the criteria for CFS and if they differed in their health locus of control. Methods: Demographic, clinical, and psychosocial measures we re prospectively collected in 90 patients, 30 each with CFS, FM, and M CS. Patients were recruited from a university-based referral clinic de voted to the evaluation and treatment of chronic fatigue and three pri vate practices. Variables included demographic features, symptoms char acteristic of each condition, psychological complaints, a measure of h ealth locus of control, and information on health care use. Results: O verall, the three patient groups were remarkably similar in demographi c characteristics and the presence of specific symptoms. Patients with CFS and FM frequently reported symptoms compatible with MCS. Likewise , 70% of patients with FM and 30% of those with MCS met the criteria f or CFS. Health care use was substantial among patients with CFS, FM, a nd MCS, with an average of 22.1, 39.7, and 23.3 visits, respectively, to a medical provider during the prior year. Health locus of control d id not differ among the three populations. Conclusions: In general, de mographic and clinical factors and health locus of control do not clea rly distinguish patients with CFS, FM, and MCS. Symptoms typical of ea ch disorder are prevalent in the other two conditions.