When your immune system reacts abnormally to medicine or drugs, it is known as a drug allergy. Mild reactions can cause nothing more than rashes, hives, fever or breathing problems, while a serious one can be life-threatening.

However, you may ignore and mistreat such allergies by confusing them for the side effects of medicines. Therefore, knowing rigorously about these allergies and the factors related to them is quite essential.

Drug or medicine allergies appear when your immune system responds abnormally to a drug. It can occur from any medication, including prescription, over-the-counter or herbal. There is no prominence of an immediate reaction after the first dose in most cases.

However, your immune system builds a specific substance called an antibody to fight the drug on its next dose, which causes such allergic reactions.

Your immune system fights with foreign substances like bacteria, parasites and viruses to protect you from diseases. A medicine allergy occurs when your immune system mistakes a drug and recognises it as an invader.

Consequently, it generates antibodies that are distinct proteins to fight the drug as a threat on its next dose. Unfortunately, these antibodies release a large amount of histamine that causes allergic symptoms in your body.

Below is a list of common symptoms of drug allergies:

• Hives and swelling
• Rashes on a small or large area on the skin
• Itching on the skin and in the eyes
• Congestion
• Runny nose
• Wheezing

Some severe symptoms of drug allergy are:

• Breathing problem
• Irregular heartbeat
• Fainting 

Symptoms of anaphylaxis, a life-threatening medicine allergy are:

• Breathing problem due to tight throat and respiratory tract
• Unconsciousness or dizziness
• High pulse or heartbeat
• Diarrhoea or vomiting
• Abdominal crump
• Nausea
• Blood pressure fall
• Lose consciousness

People who are at risk of a drug allergy have the following factors:

• Genetic factors such as Acetylator status and type of HLA
• Simultaneous medical diseases such as Asthma, Human Immunodeficiency Virus, Ebstein-Barr Virus, etc.
• Experience of drug reactions previously
• Multiple Drug Allergy Syndrome

Diagnosing medicine allergy is essential as misdiagnosis can lead to a more severe condition. Generally, a thorough physical examination and enquiry are enough for such allergies. In addition, the investigation may include questions on the occurrence and growth of symptoms and medication schedules.

However, a few other tests for drug allergy are essential to confirm them as follows:

• Skin test- A nurse or an allergist applies a tiny amount of a suspect medicine to the skin with an injection or a patch. The result determines whether you are allergic to the drug.
• Blood test- A simple way to examine and confirm allergy is to undergo testing of a blood sample taken from your body during allergy. The reports will confirm your symptoms as a medicine allergy.

Treating medicine allergy as soon as possible is necessary to prevent the symptoms from worsening. Below are some ways to treat such allergies:

• Discontinuation of the drug- If your doctor confirms your drug allergy, the first step he will take is discontinuing your current medication.
• Corticosteroids- Medicine allergies cause swelling of your respiratory tract and other inflammatory issues. Corticosteroids come as an injection, pill or nasal spray to treat such severe problems due to these allergies.
• Antihistamines- These prevent the production of the primary substance from causing infection, the histamine. Antihistamines come as pills, eye drops, cream and nasal spray.
• Bronchodilators- Your doctor may prescribe bronchodilators to ease breathing and cure coughing and wheezing. These come in the form of liquid as well as a powder in a nebuliser or inhaler.
• Treating Anaphylaxis- This severe symptom may need instant epinephrine injection and hospitalisation to support breathing and control blood pressure.

As long as you know about the treatments, you must prevent any further drug allergies. Some of such precautionary measures are as follows:

• In such cases, the first thing to do is to be clear with your doctor or healthcare provider about your allergy to a particular medicine.
• Wear a bracelet or carry a card to indicate any drug allergy you have in case of emergency.
• Ask your doctor about other medicines you should avoid along with the drug causing allergy for further precaution.

A drug allergy may not be significant initially but can turn into something calamitous. Especially when it is mistreated as a mere side effect, it can get worse. However, this article contains all the essential details to clarify medicine allergy and factors related to it. Now, recognising one and undergoing proper treatment is not as conflicting as it was before.