The search of latex sensitization in spina bifida: diagnostic approach

Background Sensitization to latex has become a major problem in children wi th spina bifida. Life-threatening reactions may occur in these patients, th erefore the search of latex sensitization must be an active task in all of these children. Objective To design an approach for the diagnosis of latex sensitization in children with spina bifida. Methods We studied 100 consecutive unselected patients. Skin prick tests wi th a commercial latex extract were performed, latex-specific serum immunogl obulin (Ig) E was determined by CAP test, and risk factors were studied. Or iginally, patients with an area of latex skin test > 50% of the area of his tamine and/or CAP class greater than or equal to 3 were considered sensitiz ed to latex. Diagnostic tests were also performed in a control group of 51 atopic and nonatopic children. Results After performing a receiver-operating characteristics curve for bot h tests we recommend skin tests > 25% of the area of histamine (sensitivity - SEN = 79%, specificity - SPE = 100%, positive predictive value - PPV = 1 00%, negative predictive value - NPV = 90%), or CAP class greater than or e qual to 2 (SEN = 88%, SPE = 100%, PPV = 100%, NPV = 94%) as diagnostic cut- off points. The anamnesis had a SEN of 44% for diagnosis, and a SPE of 100% . Latex sensitization was associated with more than 5 operations (OR = 8, 9 5% CI = 3-21.3), a personal history of atopy (OR = 11.5, 95% CI = 2.3-57.1) , and serum total IgE greater than or equal to 2 z-units (OR = 4, 95% CI = 1.6-10). Conclusion For the routine evaluation of children with spina bifida, we pro pose a diagnostic algorithm with skin prick tests as a first step and CAP s econd.