A drug allergy is an allergic reaction that is caused by the immune system responding in a negative way to a medication. All medications can cause a drug allergy in some patients, no matter how well-tolerated they are by most people. Certain medications are more likely to cause these kinds of reactions than others. The symptoms of this kind of reaction to a medication can vary, and sometimes the symptoms can be so severe that they are life-threatening.
The most common symptoms of a drug allergy are:
Sometimes a severe allergic reaction will happen, which is known as anaphylaxis. This is a life-threatening condition that requires immediate medical attention. The symptoms of anaphylaxis are:
Some people also report that they feel a sense of doom or foreboding before an anaphylactic attack. Symptoms can also include collapse or shock.
A drug allergy is caused by your immune system incorrectly identifying a drug that you have taken as a harmful substance like a virus or bacteria. When the immune system identifies this kind of risk, it will create antibodies to try and get rid of the invading pathogen. With less severe drug allergies, the symptoms of the reaction can grow worse progressively over time as the immune system becomes more and more sensitised to what it views as an attack.
If you have a more severe allergic reaction like anaphylaxis, you might have only taken the medication once, but your body has a very strong reaction to what it views as a threat to its well-being. Allergic reactions of this kind might happen because some drugs bind directly to the immune system’s T-cells, causing a cascade effect in the immune system that is immediate and profound.
The risk factors for drug allergies are:
Diagnosis of drug allergies might be made solely based on a patient’s reports of feeling common drug allergy symptoms after taking a medication. If anaphylaxis has occurred, this reaction is considered a diagnosis and your medical records should be noted to indicate that you are severely allergic to the medication that caused the anaphylactic reaction.
Diagnosis of more mild drug allergies might be made by taking skin scrapings to see if your rash or skin irritation is related to a drug allergy. Blood tests can also be taken to confirm an allergic response. Most of these diagnostics will be inconclusive, which means that you will likely be given a different medication to replace the one that is causing your symptoms.
Prevention of drug allergies is done by informing healthcare workers of any prior allergic reactions that you have had. Your medical records should be noted for all drug allergies that you have exhibited in the past. You can also wear a medical alert bracelet that identifies your drug allergy. This is necessary for severe allergies so that you are not treated incorrectly if you are not able to communicate with healthcare staff due to loss of consciousness or other impairments.
Treatment involves the use of antihistamines to halt the allergic reaction. You will be directed to withdraw from the drug gradually unless your reaction is very severe. Corticosteroids can be used to help reduce inflammation and discomfort related to an allergic reaction.
Treatment of anaphylaxis is different, as this is a life-threatening emergency. Anaphylaxis is treated with an immediate injection of epinephrine. Hospital care might be needed to monitor your health until you are stable again and the allergic reaction appears to have ended. Some people will need to carry an epi-pen for emergency use at home for the rest of their life after an anaphylactic reaction.