Drug allergy is a problem that is relevant challenge for both doctors and their patients. It is doctors who are responsible for prescribing a particular drug, and it is not always possible to foresee the development of allergic reactions to a particular drug in a particular person.

In most cases, patients themselves take drugs that are actively advertised on television and dispensed in pharmacies without a doctor's prescription. These drugs pose the greatest danger.

Thus, drug allergies in 90% of people are caused by aspirin, sulfonamide drugs (trimethoprim, septrin, biseptol) or antibiotics (penicillin, cefuroxime). It is difficult to estimate the true incidence of allergic reactions. However, it is known that four out of every ten usually overreact when asked about drug allergies or confuse allergic reactions with something else.

Allergic reactions to medications are divided into two types according to the time of onset.

1. Immediate, occurring immediately after ingestion or administration of the drug. They include anaphylactic shock, urticaria, allergic swelling.

2. Delayed, developing several days later. They are manifested by fever, urticaria, pain in the joints.

Nowadays, skin or provocation tests are used to diagnose drug allergy, which can give false positive or false negative results. The basophil activation test (CAST) with patients' medications is specifically designed to detect drug allergy.

The drug intolerance test, CAST (Cellular Antigen Stimulation Test), is also called an in vitro provocation test. The method was patented by Prof. De Weck and Dr. Sainte-Laudy in 1994. CAST has the highest specificity compared to the classical histamine release test. The method has 100% specificity. Use of the CAST test avoids the use of life-threatening provocation tests and carries no risk to the patient. The patient gives blood in the laboratory and brings with him/her the specific drug to which an allergic reaction is suspected.