| A skin prick test and (if the preparation is available in parenteral form) an intradermal test are recommended for immediate reactions. Skin prick tests shall always be performed prior to intradermal tests. |
| In the case of suspected delayed reactions, patch tests and (if the preparation is available in parenteral form) intradermal tests with delayed reading are recommended. Prior to intradermal tests, immediate-reading (and possibly also delayed-reading) skin prick tests should be performed. |
| In the case of severe delayed reactions, stepwise skin tests should be considered following an individual risk assessment. |
| If a reaction is equivocal, testing for a possible immediate or delayed reaction is recommended. |
| Performing skin tests is recommended 1 month after resolution of the skin reaction at the earliest, but preferably within 1 year of the reaction, since skin test reactivity to BLA diminishes over time [116]. This is particularly important in immediate reactions. |
| After an individual benefit–risk assessment, titrated testing with the medication shall be performed, beginning with a dilution of the maximum non-irritant test concentration, followed by a gradual increase in concentration if the result is negative. Open patch testing with a 20-min reading and subsequent initiation of skin prick testing should be considered. |
| Testing the suspected drug, if available, on the skin is recommended. |
| It may be advisable to test CLV as a single substance, if possible, after reactions to AX/CLV. |
