title: A 60-year meta-analysis of tick paralysis in the United States: a predictable, preventable, and often misdiagnosed poisoning.
abstract: Tick paralysis (TP) is a neurotoxic poisoning primarily afflicting young girls in endemic regions. Recent case series of TP have described increasing misdiagnoses of TP as the Guillain-Barré syndrome (GBS). A meta-analysis of the scientific literature was conducted using Internet search engines to assess the evolving epidemiology of TP. Fifty well-documented cases of TP were analyzed over the period 1946-2006. Cases were stratified by demographics, clinical manifestations, and outcomes. Misdiagnoses were subjected to Yates-corrected chi-square analyses to detect statistically significant differences in proportions of misdiagnoses between earlier and later reporting periods. TP occurred seasonally and sporadically in individuals and in clusters of children and adults of both sexes in urban and rural locations. The case fatality rate (CFR) for TP was 6.0% over 60 years. The proportion of misdiagnoses of TP as GBS was significantly greater (chi(2) = 7.850, P = 0.005) in more recently collected series of TP cases, 1992-2006, than the proportion of misdiagnoses in earlier series, 1946-1996. TP was a potentially lethal poisoning that occurred in children and adults in a seasonally and regionally predictable fashion. TP was increasingly misdiagnosed as GBS during more recent reporting periods. Such misdiagnoses often directed unnecessary therapies such as central venous plasmapheresis with intravenous immunoglobulin G, delayed correct diagnosis, and tick removal, and could have increased CFRs. TP should be added to and quickly excluded from the differential diagnoses of acute ataxia and ascending flaccid paralysis, especially in children living in TP-endemic regions of the USA.
authors.affiliation: LSU School of Public Health, New Orleans, LA, USA. jdiaz@lsuhsc.edu
authors.forename: James Henry
authors.initials: JH
authors.lastname: Diaz
mesh_terms: D000328:Adult; D000818:Animals; D001733:Bites and Stings / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D016009:Chi-Square Distribution; D002648:Child; D057210:Delayed Diagnosis; D003951:Diagnostic Errors; D019353:Endemic Diseases / Q000517:prevention & control; D005260:Female; D020275:Guillain-Barre Syndrome / Q000175:diagnosis; D006801:Humans; D008297:Male; D012111:Residence Characteristics; D018570:Risk Assessment; D012307:Risk Factors; D012621:Seasons; D013985:Tick Paralysis / Q000175:diagnosis / Q000453:epidemiology* / Q000401:mortality / Q000517:prevention & control; D013987:Ticks; D013997:Time Factors; D014481:United States / Q000453:epidemiology; D019564:Unnecessary Procedures