Health
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is an Allergic Disease?

Jacquelyn Gilchrist
Jacquelyn Gilchrist

An allergic disease is a hypersensitivity to a specific substance that is normally harmless. It occurs when the immune system wrongfully identifies the substance as harmful. The body’s immune system then reacts abnormally to the substance and releases chemicals, such as histamine. This causes an allergic reaction and a wide range of possible symptoms. There is no cure for an allergic disease, however, the symptoms can be treated.

While the exact reason why some people develop allergies is unclear, it may be both environmental and genetic. There are some common allergic triggers, or substances that often cause allergic reactions. These include insect stings, latex, and pollen. People may also be allergic to certain foods, medications, and pet dander. Some people are also allergic to dust mites and mold.

Keeping a journal of possible allergens can be helpful to doctors.
Keeping a journal of possible allergens can be helpful to doctors.

Specific symptoms of an allergic reaction depend on the type of allergy trigger, or allergen. The symptoms can range from mild to severe to life-threatening. A life-threatening allergic reaction is called anaphylaxis. This can result in nausea, vomiting, and difficulty breathing. Patients may also lose consciousness, be short of breath, and have a rapid but weak pulse.

Hives are one of the most common allergic reactions.
Hives are one of the most common allergic reactions.

For example, a person with a food allergy may experience a tingling mouth, hives, and a swelling in the facial area, as well as anaphylaxis. An allergic skin reaction could cause flaking and peeling, as well as itchy, red skin. Pollen allergies may trigger itchy, watery eyes, congestion, and an itchy, runny nose. Drug allergies and allergies to insect stings can both cause anaphylaxis. Patients who suffer from this reaction should get immediate medical help.

People who suspect they may have an allergic disease can undergo some tests for a diagnosis. A doctor may perform a skin test, in which he exposes tiny amounts of a potential allergen to a pricked area of skin. The reaction of the skin to the substance will determine if the patient is allergic to it.

Doctors may also run a blood test, called a radioallergosorbent (RAST) test. This can measure how the immune system reacts to possible allergens. In addition, patients can assist their doctor in a diagnosis by keeping a journal of possible allergens. If the suspected substance may be a food, the patient can go on an elimination diet, or avoid eating that particular food. Under his doctor’s guidance, the patient will then eat the food again to evaluate potential symptoms.

An essential step in treating an allergic disease is for the patient to avoid any exposure to known allergens. Patients can also be treated with medications, such as antihistamines, decongestants, and corticosteroids. If oral drugs are not sufficient to alleviate an allergic disease, the doctor may prescribe allergy shots, or injections.

People with severe, potentially life-threatening allergies should carry an epinephrine shot at all times. This emergency injection can help save a patient’s life in the event of anaphylaxis. Even if this reduces reaction symptoms, the patient must still seek immediate medical care following allergen exposure. While an allergic disease may be severe, or even potentially deadly, patients who closely monitor their own treatment can be successful at controlling symptoms.

Discuss this Article

Post your comments
Login:
Forgot password?
Register:
    • Keeping a journal of possible allergens can be helpful to doctors.
      By: pio3
      Keeping a journal of possible allergens can be helpful to doctors.
    • Hives are one of the most common allergic reactions.
      By: marilyn barbone
      Hives are one of the most common allergic reactions.