Hamilton RG. Adkinson NF Jr., Diagnosis of natural rubber latex allergy: multicenter latex skin testing efficacy study. Multicenter Latex Skin Testing Study Task Force. Journal of Allergy & Clinical Immunology. 102(3):482-90, 1998.
The authors conducted a multicenter clinical skin testing study to document the safety and diagnostic sensitivity and specificity of a candidate Hevea brasiliensis nonammoniated latex (NAL) extract to support the licensing of this reagent for the diagnosis of latex allergy in high-risk populations. The authors classified 304 adults and 20 children by their clinical history as having latex allergy (LA group, 124 adults and 10 children) or having no latex allergy (NLA group, 180 adults and 10 children). All subjects provided blood samples and then received sequential puncture skin tests (PSTs) at 1, 100, or 1000 mcg/mL protein with a bifurcated needle and NAL (Greer Laboratories) from Malaysian Hevea brasiliensis (clone 600) sap. A 2-stage glove provocation test was used to clarify latex allergy status of individuals with positive history/negative PST result and negative history/positive PST result mismatches. Twenty-four subjects (15%) originally designated as having LA on the basis of their initial clinical history were reclassified to the NLA group on the basis of a negative glove provocation test result. Of the 134 subjects with LA, 54 (40%) were highly sensitive to latex, with a positive PST result at 1 microg/mL NAL. The Greer NAL reagent produced a positive PST rate (sensitivity) of 95% and 99% in subjects with LA at 100 microg/mL and 1 mg/mL, respectively. The negative PST rate (specificity) in 190 subjects with a negative history with the NAL extract at 100 microg/mL and 1 mg/mL, was 100% and 96%, respectively. Immediately after the PST, mild systemic reactions (mainly pruritus) were recorded in 16.1 % of the adults in the LA group and 4.4% of the adults in the NLA group. No reactions required treatment with epinephrine. Only mild delayed reactions were observed in 9.6% (LA group) and 2.8% (NLA group) of subjects 24 to 48 hours after PST. Mean wheal and erythema diameters measured in the 10 children in the LA group with spina bifida at 100 mcg/mL and 1 mg/mL were similar to those observed in the adults in the LA group, suggesting that children are not at increased risk for systemic reactions compared with adults. The authors conclude that a suggestive clinical history is necessary but not sufficient for a definitive diagnosis of IgE-dependent latex allergy. The data support the safety and diagnostic efficacy of the Greer NAL, skin test reagent at 100 micro/mL and 1 mg/mL for confirmatory PSTs.