Recommendations for penicillin skin testing in Taiwan.

Penicillin, or other forms of it, is one of the most commonly prescribed antibiotic used to treat bacterial infections. Penicillin allergy may present with a wide range of symptoms and signs from mild ones such as runny nose, rash or hives on the skin, to deadly angioedema, asthmatic attack, and anaphylactic shock. The purposes of a penicillin skin test (PST) are to identify people at risk of a severe to immediate-type allergic reaction to penicillin, to determine the safety of penicillin and its derivatives for those who have ever had allergies to antibiotics, to increase therapeutic choice of antibiotics for infection, to reduce antimicrobial expenditure and to reduce drug resistance. The standard PST can give a positive predictive value of nearly 100% and a negative predictive value of 97e99%. The standard reagents used in PST include major determinant, minor determinant, positive control, and negative control. The standard procedure for administering a PST is to first perform a prick test followed by an intradermal test. Due to the lack of availability of major and minor determinant testing reagents in Taiwan, PST is usually performed with diluted penicillin G and directly followed by an intradermal test. With its low value in predicting severe penicillin allergy, risk remains when performing this modified PST. Disputes regarding this test have existed in the medical society for decades. Therefore, a consensus conference to establish clinical practice guidelines for penicillin skin testing in Taiwan was held on March 5, 2011. This meeting followed a symposium on the