For typical allergic reactions, your health-care provider will examine you and ask questions about your symptoms and their timing. Blood tests and X-rays are not needed except under unusual circumstances.

In case of severe reaction, you will be evaluated quickly in the emergency department. The first step for the health-care provider is to judge the severity of the allergic reaction.

• Blood pressure and pulse are checked.

• An examination determines whether you need help breathing.

• Often, an IV line is placed in case you need antiallergy medications quickly.

• If you can speak, you will be asked about triggers and previous reactions.

• Blood tests and X-rays are typically not helpful.