A prospective study of tender points and fibromyalgia during and after an acute viral infection.

BACKGROUND Tender points (TPs) and fibromyalgia (FM) may be precipitated by infections, but the frequency, associated characteristics, and predictors of these outcomes are unknown. OBJECTIVES To determine if acute infectious mononucleosis (AIM) is associated with the development of TPs or FM acutely or during the subsequent 6 months; if demographic, clinical, or psychosocial features predict TPs or FM; and if TPs or FM correlate with nonrecovery. METHODS A total of 150 subjects diagnosed as having AIM were assessed with physical examinations (including palpation of 18 TPs), laboratory tests, and measures of psychosocial and somatic functioning at enrollment and at 2 and 6 months. Subjects also completed a structured psychiatric interview at the initial evaluation. RESULTS At presentation and at 2 and 6 months, the mean TP counts were 7.5, 4.6, and 3.0, respectively; at these time points, 19%, 3%, and 1% of subjects also met modified criteria for FM. Tender points and degree of pain diminished over time following AIM. Acutely, TPs were associated only with higher temperature (P<.001). Baseline features that predicted more TPs at 2 and 6 months were female sex, older age, less family social support, and more TPs at presentation. Neither initial laboratory tests nor psychiatric disease or distress predicted TPs. Differences between those who had and had not recovered at 6 months were found for the mean number of TPs (P<.008), the proportion of subjects with 11 or more TPs (P<.002), and the degree of pain. CONCLUSIONS Tender points are a common, transient finding associated with AIM, but FM is an unusual long-term outcome. Demographic, social, and physical examination features predicted TPs.