Allergy is a hypersensitivity disorder in which the body’s immune system reacts to normally harmless substances in the environment. These substances which trigger an allergic reaction in the body are called allergens. Allergy can be caused by anything such as egg, wheat, peanuts, milk, drugs, house dust mites, unhygienic places, cold, rain and even dust. Food allergies are reactions towards certain food components. The most common allergens in foods are proteins. When the allergic reaction is due to a drug, it is said to be a drug allergy. They are most commonly seen with antibiotics followed by anti-tumour drugs.
Allergens cause an immune system response in the person’s body leading to symptoms such as sneezing, skin rash, hives, and itching of the skin or eyes, swelling of face or tongue, running nose, hoarseness of voice, cough, etc. Allergies can play a major role in conditions such as asthma. Drug allergy may cause swelling or tightening of the airways, dizziness or light headedness, rapid pulse, or even loss of consciousness. An anaphylactic attack or anaphylaxis is a severe type of allergic reaction which can often be sudden and cause severe symptoms like choking, organ failure and even death.
Depending on the type of allergy diagnostic tests may include skin tests, blood tests, oral challenge test, drug provocation test, etc. Self-medication for allergy should be avoided. Allergy can be of many types and each one of them need separate medication to be cured. Special diets are the most commonly used treatment for food allergies. But, certain medications and supplements are also used to deal with food allergy symptoms. Adverse reaction to any drug must be notified to the doctor immediately. Epinephrine (adrenaline) injection is used to handle medical emergencies due to complications. An anaphylactic attack is a medical emergency.