Previous evaluation of in vivo sensitization to NRL Hev b proteins has utilized recombinant antigens (Yip et al. Int Arch Allergy Immunol 2000;121:293). The aim of this study is to evaluate skin prick test (spt) reactivity to Hev b proteins 1,2,3,4,6,7b, 7c isolated and purified from non-ammoniated latex (NAL) and to a recombinant Hev b5, in 130 HCWs with cutaneous sensitization to NAL. Preliminary results are presented in 21 HCWs including: 16 NAL spt + HCWs with clinical allergic reactions to NRL gloves (Group 1); and 5 HCWs with clinical reactions to NRL gloves who were spt neg. to NAL (Group 2). Endpoint prick test threshold concentrations (EPC) were determined with 7 increasing concentrations (I x 10(-6) to Img/ml of NRL) and Hev b proteins (5xl0(-5) to 50 ug protein/ml). All subjects were atopic. Fifteen of 16 Group 1 pts. had EPCs for Hev b proteins ranging between 5xl0(-5) and 50ug/ml of NAL. More than 50% of Group I pts. were spt + to Hev b 2 (69%), Hev b 4 (56%), Hev b 5 (69%), Hev b 6 (81 %), Hev b 7b(8l%), Hev b7c (62%) but not to Hev b 1 (25%) and Hev b 3 (31 %). In Group 1, 8/15 pts. were spt + to at least 4/7 Hev b proteins. Interestingly, all Group 2 pts. who were spt neg. to NAL were spt + to at least one Hev b protein with 4/5 reacting to Hev b 7. To date, this study shows the highest frequency of skin test reactivity to Hev b 6 and 7b. Hev b skin test reagents could be sensitive markers of NRL sensitization in symptomatic HCWs exposed to latex. However, extensive validation studies with these antigens are required.