Implications of gender in chronic Lyme disease.

BACKGROUND "Post-Lyme disease syndrome" refers to prolonged subjective symptoms after antibiotic treatment and resolution of an objective manifestation of Borrelia burgdorferi infection (Lyme disease). "Chronic Lyme disease" is a vaguely defined term that has been applied to patients with unexplained prolonged subjective symptoms, whether or not there was or is evidence of B. burgdorferi infection. OBJECTIVE To determine if the population of patients with chronic Lyme disease differs from the populations of patients with either Lyme disease or post-Lyme disease syndrome by examining the gender of patients with these diagnoses. METHODS Data on gender were compiled in this cross-sectional study based on a systematic review of published studies of antibiotic treatment in United States patients with post-Lyme disease syndrome (n = 184) or chronic Lyme disease (n = 490), and on cases of adults with Lyme disease reported to the Centers for Disease Control and Prevention from 2003 to 2005 (n = 43,282). RESULTS Patients with chronic Lyme disease were significantly more likely to be female than were patients diagnosed with either Lyme disease (odds ratio [OR] 2.42, 95% confidence interval [CI] 1.98-2.94, p < 0.0001) or with post-Lyme disease syndrome (OR 2.32, 95% CI 1.62-3.34, p < 0.0001). CONCLUSIONS Patients with chronic Lyme disease differ with regard to gender from those with either B. burgdorferi infection or post-Lyme disease syndrome. This finding suggests that illnesses with a female preponderance, such as fibromyalgia, chronic fatigue syndrome, or depression, may be misdiagnosed as chronic Lyme disease.