infectious diseases
Lyme Disease
Diagnosis of Lyme Disease
Clinical evaluation, supported by acute and convalescent serologic testing Erythema migrans is usually diagnosed clinically because it develops before serologic tests become positive ( Diagnosis references , Cultures of blood and relevant body fluids (eg, CSF, joint fluid) may be obtained, primarily to diagnose other pathogens. Acute (IgM) and convalescent (IgG) antibody titers 2 weeks apart may be helpful ( Diagnosis references ); positive enzyme-linked immunosorbent assay (C6 ELISA) titers should be confirmed by a second enzyme immunoassay (EIA) or Western blot test. However, seroconversion may be late (eg, Consequently, diagnosis of Lyme disease depends on both test results and the presence of typical findings. A classic erythema migrans rash strongly suggests Lyme disease, particularly when supported by other elements (eg, recent tick bite, exposure to endemic area, typical systemic symptoms). In areas where Lyme disease is endemic, many patients report arthralgias, fatigue, difficulty concentrating, or other nonspecific symptoms. Few patients who have these symptoms but have had no history of erythema migrans or other symptoms of early-localized or early-disseminated Lyme disease actually have Lyme disease. In such patients, elevated IgG titers (with normal IgM titers) indicate past exposure, not current or persistent infection, and may, if misinterpreted, lead to long and unnecessary courses of antibiotic therapy. There is no evidence linkingB. burgdorferiinfection to this fibromyalgia-like or chronic fatigue–like syndrome. In the absence of rash, diagnosis is more difficult. Early-disseminated disease may mimic Juvenile Idiopathic Arthritis (JIA) in children and In the US, human granulocytic Ehrlichiosis and Anaplasmosis (a rickettsial infection) and Babesiosis (if they have hemolytic anemia and thrombocytopenia) Human granulocytic anaplasmosis (if they have elevated aminotransferase levels, leukopenia, inclusion bodies in neutrophils, and/or thrombocytopenia) Rheumatic Fever is considered in the occasional patient with migratory polyarthralgias and either an increased PR interval or chorea (as a manifestation of meningoencephalitis). However, patients with Lyme disease rarely have heart murmurs or evidence of a preceding streptococcal infection. Human monocytotropic Ehrlichiosis and Anaplasmosis , which is caused by In southern and mid-Atlantic states, bites from theA. americanumtick may result in an erythema migrans–like rash accompanied by nonspecific self-limited systemic symptoms and signs. No specific infectious agent has yet been identified as the cause of this disorder (called southern tick-associated rash illness [STARI]). Lyme disease may cause Bell palsy and, in summer, can manifest with a musculoskeletal aseptic meningitis syndrome that mimics other causes of lymphocytic meningitis or that mimics peripheral neuropathies. 1.Sanchez E, Vannier E, Wormser GP, et al: Diagnosis, treatment, and prevention of Lyme disease, human granulocytic anaplasmosis, and babesiosis: A review.JAMA315 (16):1767–1777, 2016. doi: 10:1001/jama.2016.2284 2.Bush LM, Vazquez-Pertejo MT: Tick borne illness—Lyme disease.Dis Mon64(5):195–212, 2018. doi: 10.1016/j.disamonth.2018.01.007 3.Branda JA, Steere AC: Laboratory diagnosis of Lyme borreliosis.Clin Microbiol Rev34(2):34:e00018-19. doi: 101128/CMR.00018-19 