title: Stages in the recognition of epidemic pellagra in the United States: 1865-1960.
abstract: Recognition of the U.S. pellagra "epidemic" in the early part of this century occurred in stages. The recognition process distorted impressions of magnitude, rate of spread, and virulence. Unrecognized cases: Endemic pellagra developed from dietary deficiencies after the Civil War. Initially, cases were misdiagnosed as other more traditional disorders. Tradition and authority inhibited recognition. Recognition of severe cases: Beginning in 1907, outbreaks were reported in asylums. Existing severe cases came rapidly to medical attention, inflating the apparent rate of spread. Recognized cases had a fulminant course and a high case fatality. Expanded spectrum: Milder cases were increasingly recognized, leading to an exaggerated rate of increase in number of cases and a decrease in case fatality and apparent virulence. Greater sensitivity resulted largely from a shift in diagnostic thresholds, with loss of specificity and increase in false positive diagnoses. Standardization of diagnosis: Although no suitable diagnostic marker test was developed, diagnosis was ultimately standardized by development of a workable case definition and by assessment of response to an effective therapy (nicotinic acid) applied to presumptive cases.
authors.affiliation: Department of Neurology, University of Kentucky Medical Center, Lexington 40536-0284, USA.
authors.forename: D J
authors.initials: DJ
authors.lastname: Lanska
mesh_terms: D004196:Disease Outbreaks / Q000266:history*; D049672:History, 19th Century; D049673:History, 20th Century; D010383:Pellagra / Q000175:diagnosis / Q000453:epidemiology / Q000266:history*; D014481:United States