A serious allergic reaction that onsets rapidly and can be even fatal is called anaphylaxis. It causes a number of symptoms, typically consisting of throat swelling, itchy rashes and low blood pressure. Insect bites or stings, foods and medications are some of the common causes. Its mechanism can be explained as a reaction occurring because of release of mediators or signals from certain white cells. This may be triggered by either an immunologic or non-immunologic mechanisms. Anaphylaxis can be diagnosed depending on the exhibited signs and symptoms. Administration of intravenous fluids, positioning of the patient flat and epinephrine injections may be considered as primary treatment.