An allergic reaction can be a terrifying experience. A hyperactive histamine response can be an imminent matter of life and death. Allergy tests exist whereby doctors can determine exactly what food and substances trigger an adverse reaction in your body. This is accomplished by placing a small amount of the suspected allergen under a thin layer of the skin on your forearm or back. Since everyone reacts differently to these tests, it is important to know what to expect.
Histamine creates swelling, and swelling creates itching. The concept is that if you are allergic to the material placed under your skin, you will develop a centralized hive within 15 minutes. If you are not allergic to that substance, no hive will appear. Some people have a delayed reaction to a substance they are allergic to, but the hive would still appear within 24 hours. If this happens to you, this delay should be discussed with your doctor to determine if it is only a mild allergy, or if you should be retested for clarity. In the meantime, relatively small bumps and hives can be treated topically with cortisone cream to reduce the allergic reaction and calm the itch.
Swelling and Pain
Occasionally, the allergic response to a testing component causes swelling, aching and tenderness in a larger region of the testing site. If this happens, ice packs, hydro-cortisone cream and antihistamines can be used to fight the pain and reduce the inflammatory response.
Sterile needles, clean hands, gloves and rubbing alcohol should all be used by your allergist's office to prevent germs from being passed along. However, any time the skin is punctured it is open to the possibility of infection. Bacterial infections as a result of allergy tests are extremely rare, but if you notice any discoloration, liquid-like swelling, fever, nausea or distinct red streaks down your arm, call your doctor immediately or go to an emergency room. Antibiotics can usually cure basic bacterial infections, but if the infection reaches your bloodstream it can become a much more serious matter and could require an intravenous treatment.
In the worst-case scenario, an extreme allergic reaction can result in a systemic reaction whereby your body begins to shut down. Overall swelling, shortness of breath, dizziness, faintness, tingling and closing of the throat are all possible signs of anaphylactic shock. In shock, your skin becomes pale and cool and your blood pressure lowers to a dangerous point. This reaction requires immediate medical attention. The chances are, if your body were to react this way, it would occur right away in the doctor's office, where they have the equipment and medications to deal with such a scenario. Once you have left the testing office, the chances of developing such a severe reaction are very small. This usually only occurs in extreme cases where your body cannot tolerate any degree of a certain substance without reacting with immediate fierceness. If you experience an anaphylactic reaction outside of the doctor's office, call 911 and lay down with your feet elevated until medical help has arrived.