Caffeine, in its various forms, is a widely consumed psychoactive substance. Caffeine is a chemical which is found naturally in tea, coffee, cacao (chocolate), and as an additive to many cola or energy drinks. It acts as a stimulant and diuretic. It is generally considered safe, but in some rare cases, and in extremely high doses, it can be toxic, cause allergies, and even cause death.
Actual allergy means the immune system’s response to an IgE antibody. However, toxicity due to overdose is very different from that due to allergy. Overdose of caffeine can cause restlessness, excitement, agitation, mental confusion, irritability, hallucinations, difficulty in sleeping and other symptoms resembling mental illness.
Caffeine allergy symptoms however are different, and may range from a minor rash to seizures which could be life threatening. Sometimes, the reactions are so slight, like an itchy skin or a slight tingling in the mouth, that people do not even notice them. Other more serious reactions of caffeine allergy include shock, swelling of the face, tongue or throat, and difficulty in breathing.
Sometimes, the reactions are caused by allergy to another component of caffeine, that is, tannin, which is also found in red wine, soda and chocolate. Sometimes, the allergies may also be caused by pesticides and herbicides which have been used to grow the coffee beans.
What a person is actually allergic to, and to what extent, will determine the severity of the attack.
Actual allergy means the immune system’s response to an IgE antibody. Caffeine allergy tests like an oral challenge test or a skin prick test will determine whether a person is indeed suffering from a caffeine allergy.
This is usually the first test carried out to determine an allergy and is done by a medical health care provider. A small area of the inner forearm is cleaned with antiseptic. A tiny prick is made, and the suspected allergen (in this case caffeine) is introduced. If the skin becomes itchy, red or swollen within a period of 15 to 60 minutes, it means that the results are positive. A few days prior to the test, you must stop taking any anti-histamines, which may affect the results of the allergy test. Only a very minute amount of the allergen is used in order to prevent any serious reactions.
If the skin prick test is not effective, you may be asked to go for a blood test. Your health care provider will draw some blood from your elbow and send it to the lab for testing. Results may take 7 to 14 days.