Likelihood ratios and Fagan's nomogram: valuable but underrated tools for in vitro latex sensitization assessment

The relevance of latex allergy has greatly increased in the last decade esp ecially in health workers and in children with spina bifida. Serological te sting has been proposed in the diagnosis since history can be inconclusive and skin and provocative testing can induce severe adverse reactions. We ev aluated positive likelihood ratios (LRpos) and the Fagan's nomogram in the diagnosis of latex allergy. Thirty patients with positive clinical history, who showed positive results in the skin prick test and in glove-exposure t est were compared, to 36 blood donors with negative clinical history, who s howed negative results in the skin prick test and in glove-exposure test. L Rpos was calculated at four different cutoff concentrations of IgE specific to latex measured with a totally automated analyzer. LRs appear better com pared to the traditional classes in the reporting of IgE and, coupled with the Fagan's nomogram which allows the calculation of post-test probability, could improve laboratory testing in latex allergy. (C) 1999 Elsevier Scien ce B.V. All rights reserved.