BACKGROUND: Chronic fatigue syndrome (CFS), fibromyalgia (FM), and
multiple chemical sensitivities (MCS) are conditions
associated with fatigue and a variety of other symptoms that
appear to share many clinical and demographic features. Our
objectives were to describe the similarities 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 were prospectively collected in 90
patients, 30 each with CFS, FM, and MCS. Patients were
recruited from a university-based referral clinic devoted to
the evaluation and treatment of chronic fatigue and three
private practices. Variables included demographic features,
symptoms characteristic of each condition, psychological
complaints, a measure of health locus of control, and
information on health care use.
RESULTS: Overall, the three
patient groups were remarkably similar in demographic
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 for CFS. Health care use
was substantial among patients with CFS, FM, and 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 did not differ among the three populations.
CONCLUSIONS: In general, demographic and clinical factors and
health locus of control do not clearly distinguish patients
with CFS, FM, and MCS. Symptoms typical of each disorder are
prevalent in the other two conditions.
Buchwald D, Garrity D