When It Isn’t Always Lyme: Expanding the Differential Diagnosis for Acute-Onset Polyarthralgia in the West Virginia Eastern Panhandle

This case presentation discusses a 36 year-old female animal care worker presenting with an acute-onset polyarthropathy during the summer months in a Lyme endemic region. Though she appeared to be a good candidate for the diagnosis of Lyme borreliosis, her screening serology reported negative results and alternative diagnoses were considered. Her subsequent diagnosis with parvovirus B19 acts to remind the general practitioner to have confidence in the accuracy of a negative Lyme screen and, upon negative result, to expand the differential to include less common infections including parvovirus B19. It also highlights the need to remember parvovirus B19 in a similar patient who has the potential to be or to become pregnant during the course of her illness