The search of latex sensitization in spina bifida: diagnostic approach

BACKGROUND: Sensitization to latex has become a major problem in children with spina bifida. Life-threatening reactions may occur in these patients, therefore 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 with a commercial latex extract were performed, latex-specific serum immunoglobulin (Ig) E was determined by CAP test, and risk factors were studied. Originally, patients with an area of latex skin test > 50% of the area of histamine and/or CAP class > or = 3 were considered sensitized 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 both tests we recommend skin tests > 25% of the area of histamine (sensitivity - SEN = 79%, specificity - SPE = 100%, positive predictive value - PPV = 100%, negative predictive value - NPV = 90%), or CAP class > or = 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, 95% CI = 3-21.3), a personal history of atopy (OR = 11.5, 95% CI = 2.3-57.1), and serum total IgE > or = 2 z-units (OR = 4, 95% CI = 1. 6-10). CONCLUSION: For the routine evaluation of children with spina bifida, we propose a diagnostic algorithm with skin prick tests as a first step and CAP second.