About Insect Stings: Making the Diagnosis
Tests are not normally required to diagnose bee stings. Diagnostic tests are only likely to be of value in this area if someone finds a mite or tick on their skin and want to know if it's carrying anything dangerous. If a tick is pulled out of the skin (see "Treatment and Prevention" for how to do it), it should be checked for Borrelia burgdorferi, the cause of Lyme disease, if the person was in an infested area.
Another kind of diagnostic test that might be valuable is to be tested for insect venom allergy. This involves scratching the skin with tiny doses of various insect venom and looking for a rash. People with major sensitivity to common insects might even be advised to carry a rescue kit in the summertime.