Every medication/drug allergy diagnosis should begin with a detailed medical history and physical examination. The doctor will ask lots of questions about the nature of the reaction, where and when it occurs, etc. Since the drug allergy may be genetic, expect some questions about other family members who may be allergic.
Depending upon the findings of the initial evaluation, the following tests may be necessary:
Allergy skin testing may be performed to check for presence of allergic antibodies to selected drug allergens.
Blood testing is occasionally indicated.
A drug challenge to the suspected drug is sometimes necessary to confirm the diagnosis. If indicated, drug challenges are coordinated with safety as the highest priority.
The best way to treat drug allergy is to avoid the medication, since there is no cure for allergy. Antihistamines and steroids can be used to alleviate symptoms, but once a drug allergy is determined, the medication should be avoided.