Objective and methods: In order to study risk factors for latex allergy in patients with spina bifida, we investigated 165 patients with spina bifida (mean age 9 years). Besides answering a questionnaire, patients underwent skin-prick testing and determination of specific serum IgE to latex as well as a screening test for specific IgE to environmental allergens. A total of 80 patients (49%) were sensitized to latex according to the presence of specific IgE to latex.
Results: Skin-prick tests (SPT) with high ammonia latex milk were performed in 81 of our patients with spina bifida and were positive in 36 patients (46%). Concordance of SPT with specific IgE in serum was good. Nineteen out of 165 patients suffered from a clinically relevant latex allergy: five patients had a history of systemic reactions to latex (e.g. severe bronchospasm, anaphylactic reactions), mostly during surgery. Fourteen patients reported clinical symptoms while inflating a balloon; all these 19 patients were sensitized to latex. Number of operations ranged from one to 26 (mean 5 operations). Concentration of specific IgE to latex in serum correlated well with increasing numbers of operations. Some 32/76 patients (41%) with spina bifida who were sensitized to latex showed an atopic disposition, while 21 out of 81 latex-negative patients (26%) were atopic. Of 300 consecutive sera (mean age of patients 9 years) sent to our laboratory for routine determination of specific IgE, 144 (48%) were positive in terms of specific IgE to environmental allergens, of which 247144 (17%) were sensitized to latex.
Conclusions: From our data we conclude that in order to minimize risk of severe systemic clinical reactions, all patients with spina bifida should be screened for their individual risk of latex allergy to plan preventive measures before operations. Main risk factors for latex allergy seem to be: more than five operations, atopic predisposition, history of clinical symptoms while inflating a balloon, and a sensitization with a CAP-class of > or = 4.