Clinical Characteristics of Patients with Medically Unexplained Chronic Widespread Pain: A Primary Care Center Study

BACKGROUND: Chronic widespread pain (CWP) is known as a common symptom of several organic and psychological disorders. Although medically unexplained CWP (MUE) has lots of clinical distress symptoms, there were no distinct symptoms or signs. Therefore, we conducted this study to investigate clinical distress symptoms of MUE distinct from those of medically explained CWP (ME). METHODS: One hundred nine patients with CWP were enrolled in the study. We classified the study subjects into three groups depending on their medical problems associated with CWP: organic group (ORG), psychological group (PSY), and MUE. All subjects were asked to fill out self-report questionnaires consisting of clinical distress scales including the Korean version of the Fibromyalgia Impact Questionnaire (FIQ-K), fatigue scale, depression scale, and stress scale. And physicians examined 18 tender points over their entire body of the subjects. RESULTS: MUE patients had higher FIQ-K and fatigue severity scores than ORG patients (all P < 0.05). The average number of tender points were 11.33 in MUE patients, 6.48 in ORG patients and 5.02 in PSY patients and statistically significant (P < 0.0001). There were no statistically different factors between MUE and PSY patients with exception for the number of tender points. Depressive symptom was the highest in PSY patients but not statistically different from MUE patients. CONCLUSION: MUE patients had higher physical impairments, fatigue severity and more number of tender points than ORG patients, but had no different clinical characteristics from PSY patients except for the number of tender points.