Fibromyalgia.

There has been confusion surrounding regional medical conditions, primary psychological conditions, and fibromyalgia in practice and in the literature. Confusing terminology and inappropriate use of diagnostic criteria have contributed to this problem. Use of the 1990 ACR Criteria for the Classification of Fibromyalgia together with the symptom and physical examination definitions in that report should go far to correct these problems. Problems of selection and identification bias filter patients with the syndrome, and almost all reports concerning the disorder have been obtained from subspecialty clinics. Almost nothing is known about fibromyalgia in the community, and characteristics of patients noted in the clinic may be a primary function of these biases. In general, in the clinic, about 90% of patients are women of a mean age slightly less than 50 years. Onset is noted in childhood and in old age, but most commonly in middle life. Trauma, surgery, and infection have been noted in association with development of the syndrome in some reports. More than 10% of patients attending general medical clinics and 15-20% attending rheumatology clinics have the syndrome. Chronicity is the rule. Work disability occurs, but most patients seem to be able to work, although some have changed jobs to accomplish this. Psychologic abnormalities are noted in most, but not all, reports, but may reflect selection bias and could be absent in the community.