Introduction of a practice guideline for penicillin skin testing improves the appropriateness of antibiotic therapy

We hypothesized that the introduction of a practice guideline for penicilli n skin testing would increase the appropriateness of skin testing and reduc e antibiotic costs for patients with a history of penicillin allergy who ha ve infections caused by penicillin-susceptible pathogens. We measured the a ppropriateness of skin testing and daily antibiotic costs before and after the introduction of a guideline for penicillin skin testing. For patients w ho had negative results of skin testing and were subsequently treated with a penicillin instead of an alternative antibiotic, we calculated the differ ence between the actual costs and the projected costs of continuing alterna tive antibiotics without skin testing. After the guideline was introduced, appropriateness of skin testing increased from 17% to 64%, but daily antibi otic costs did not change. For patients who had negative results of skin te sting and who were subsequently treated with a penicillin, there was no dif ference between actual costs and the projected costs if they had not been s kin tested. We conclude that introduction of a guideline for penicillin ski n testing increases the percentage of eligible patients who have a skin tes t, and it does so without increasing costs.