Delayed hypersensitivity responses in children after local cutaneous anesthesia.

The effect of cutaneous analgesia on delayed type hypersensitivity (DTH) reactions as challenged by injections in the skin was assessed by comparing a lidocaine/prilocaine mixture with placebo. Application of 5 g of the mixture 90 min before testing significantly (p less than 0.001) reduced pain but did not influence the DH-reactions as read after 48 hours. Based on these findings, DTH to several antigens were measured in 116 school children, aged 7-15 years. All the children were positive to either tetanus antigen, 7.5 Lf/ml (98% at 48 hours) or mumps test antigen (82%), while positivity to tuberculin 2 TU/ml and candida 1000 PNU/ml were only 11 and 62% respectively. Therefore, DTH tests in an adequately immunized population of children can be limited to two antigens. Application of cutaneous analgesia is recommended as a routine procedure in DTH testing in young children.