Overlapping conditions among patients with chronic fatigue syndrome, fibromyalgia, and temporomandibular disorder

Background: Patients with chronic fatigue syndrome (CFS). fibromyalgia (FM) , and temporomandibular disorder (TMD) share many clinical illness features such as myalgia, fatigue, sleep disturbances, and impairment in ability to perform activities of daily living as a consequence of these symptoms. A g rowing literature suggests that a variety of comorbid illnesses also may co mmonly coexist in these patients, including irritable bowel syndrome, chron ic tension-type headache, and interstitial cystitis. Objective: To describe the frequency of 10 clinical conditions among patien ts with CFS, FM, and TMD compared with healthy controls with respect to pas t diagnoses, degree to which they manifested symptoms for each condition as determined by expert-based criteria, and published diagnostic criteria. Methods: Patients diagnosed as having CFS, FM, and TMD by their physicians were recruited from hospital-based clinics. Healthy control subjects from a dermatology clinic were enrolled as a comparison group. All subjects compl eted a 138-item symptom checklist and underwent a brief physical examinatio n performed by the project physicians. Results: With little exception, patients reported few past diagnoses of the 10 clinical conditions beyond their referring diagnosis of CFS, FM, or TMD . In contrast, patients were more likely than controls to meet lifetime sym ptom and diagnostic criteria for many of the conditions, including CFS, FM, irritable bowel syndrome, multiple chemical sensitivities, and headache. L ifetime rates of irritable bowel syndrome were particularly striking in the patient groups (CFS, 92%; FM, 77%; TMD, 64%) compared with controls (18%) (P < .001). Individual symptom analysis revealed that patients with CFS, FM , and TMD share common symptoms, including generalized pain sensitivity, sl eep and concentration difficulties, bowel complaints, and headache. However , several symptoms also distinguished the patient groups. Conclusions: This study provides preliminary evidence that patients with CF S, FM, and TMD share key symptoms. It also is apparent that other localized and systemic conditions may frequently co-occur with CFS, FM, and TMD. Fut ure research that seeks to identify the temporal relationships and other pa thophysiologic mechanism(s) linking CFS, FM, and TMD will likely advance ou r understanding and treatment of these chronic, recurrent conditions.