Allergy

High-efficiency particulate arresting (HEPA) filter
A high-efficiency particulate arresting (HEPA) filter is a type of air filter. Air filters remove microscopic particles, such as bacteria, dust mites, and animal dander from the air. HEPA filters are often used to purify the air in the home or in healthcare facilities to help prevent the spread of infections, diseases, and/or allergies.

Epinephrine auto-injector
Epinephrine is in a class of medications called sympathomimetic agents because the medication mimics the properties of the sympathetic nervous system. Epinephrine is a medication used in emergencies to treat or prevent severe allergic reactions that can result in anaphylaxis.

Dust mite allergy
An allergy, or hypersensitivity reaction, occurs when the body's immune system overreacts to a substance that is normally harmless (allergen), such as mold, pollen, animal dander or dust mites. The white blood cells of an allergic individual produce an antibody called immunoglobulin E (IgE), which attaches to the allergen. This triggers the release of histamine and other inflammatory chemicals that cause allergic symptoms, such as runny nose, watery eyes and hives.

Diagnosing immune disorders and allergies
There are many tests available to diagnosis problems with the body's immune system. Different tests are used to diagnosis different types of disorders, including autoimmune disorders, allergies, genetic disorders, and antibody deficiencies.

Common variable immunodeficiency
Common variable immunodeficiency (CVID), also called hypogammaglobulinemia or adult-onset hypogammaglobulinemia, is a relatively common primary immune deficiency. The disorder is characterized by a lack of antibody-producing B-cells or plasma cells, low levels of most or all immunoglobulin isotypes and recurrent bacterial infections.

Complement deficiencies
Complement deficiencies are disorders that occur when the body has low or nonexistent levels of specific proteins needed for proper immune function. Healthy immune function is important to protect the body from disease and infections. These proteins, which are part of the complement system, help destroy harmful invaders, such as bacteria and viruses, that enter the body.

Hypersensitivity reaction to chemotherapy
Chemotherapy is often used to treat various types of cancer. These drugs, also called anti-cancer drugs, destroy cancer cells by preventing them from growing and multiplying. However, healthy cells are also harmed during the process, which is responsible for the side effects of treatment. Once chemotherapy is discontinued, healthy cells usually repair themselves and side effects gradually subside.

B-cells
The white blood cells that are involved in an acquired immune response are called lymphocytes. There are two types of lymphocytes - B-cells and T-cells. Both of these cells are continually produced in the bone marrow.

Antigen-presenting cells
Antigen-presenting cells (APC) are specialized white blood cells that help fight off foreign substances that enter the body. These cells send out signals to T-cells (other immune system cells) when an antigen enters the body. Each type of T-cell is specially equipped to deal with different pathogens, which may be a bacteria, virus or toxin.

Antibody deficiencies
Antibody deficiencies, also called immunoglobulin deficiency syndromes, are immune system disorders that are characterized by low or absent levels of immunoglobulin in the blood. Immunoglobulins (Ig) are antibodies that play an essential role in the body's immune system. They detect and bind to foreign substances (like bacteria, viruses, fungi, or allergens) that enter the body. This signals other immune cells to destroy the foreign substance. The antibodies are present in the bloodstream or bound to the outer surfaces of B-cells or plasma cells.

Anaphylaxis - from Natural Standard
Anaphylaxis is a rapid, immune-mediated (allergic), systemic reaction to allergens (like food, medication or insect stings) that the individual has previously been exposed to. Anaphylaxis is a medical emergency that requires immediate medical treatment, as well as follow-up care with an allergist or immunologist.

Allergies and pregnancy
An allergy or hypersensitivity reaction occurs when the body's immune system overreacts to a substance that is normally harmless (allergen), such as mold, pollen, animal dander, or dust mites. Allergy symptoms may include runny nose, watery eyes, urticaria (hives), angioedema (swelling beneath the skin), and atopic dermatitis (red, itchy dry skin). The most severe allergic reaction, known as called anaphylaxis, can lead to low blood pressure, breathing difficulties, shock, and loss of consciousness, all of which can be fatal.

Allergic rhinitis (hay fever)
Rhinitis is the medical term for inflammation of the nose. Viruses, bacteria, allergens, and irritants can cause inflammation of the nasal mucus membrane, which results in rhinitis. Once inflamed, the nose produces excessive mucous, which causes a runny nose, nasal congestion, and postnasal drip (when mucus drips from the sinuses, down the throat).

Serum sickness
Serum is the clear fluid portion of blood. While it does not contain blood cells, it does contain many proteins, including antibodies, which are formed as part of the immune response to help protect against infections.

Allergen-specific IgE antibody test
An allergen-specific immunoglobulin E (IgE) test, commonly often referred to as radioallergosorbent test (RAST�) is a type of blood test that can help determine if a patient who experiences allergy symptoms, such as runny nose, watery eyes and hives, is allergic to particular substances called allergens.

Pet dander allergy
Animals secrete oily fluids from their skin, which contain allergens called dander. These fluids collect on fur, feathers and other surfaces inside the home, and they can cause allergic reactions in sensitive people. Proteins in the animal's saliva also cause allergic reactions. These allergens are so small that they can become airborne for extended periods of time.

Nasal decongestants
Decongestants relieve nasal and sinus congestion (stuffy nose) caused by allergies or colds. These drugs shrink the tissues and blood vessels in the eyes and nose that swell in response to a cold or contact with an allergen (substance that causes an allergic reaction).

Lipid mediators
Lipid mediators are chemical messengers that are released in response to tissue injury. When a harmful invader, such as bacteria, enters the body, some lipid mediators are released to help stimulate cells involved in the immune response while others help "turn off" an immune response when it is no longer needed. Current evidence suggests that lipid mediators, including prostaglandins (PGs), leukotrienes, and lipoxins, play an essential role in the different phases of inflammation.

Intravenous immunoglobulin therapy
Intravenous immune globulin (IVIG) is made of antibodies that have been extracted from blood donations from 3,000-10,000 healthy donors. IVIG is used to treat many autoimmune disorders, idiopathic diseases (disease of unknown cause), and infections.

Allergen immunotherapy
Allergen immunotherapy, also known as allergy shots, is often used to treat patients who suffer from severe allergies or who experience allergy symptoms more than three months a year. Allergen immunotherapy involves injecting increasing amounts of a diluted allergen into a patient over several months.

Immunoaugmentative therapy (IAT)
Immunoaugmentative therapy (IAT) is an unproven cancer treatment that involves injecting blood proteins from healthy human donors into a patient. Although this therapy has not been proven to be effective, proponents believe it helps restore the body's natural immune defenses against cancer.

Immune response
The immune response is a defensive reaction against harmful substances, such as viruses or bacteria, which enter the body. The immune response helps protect the body from disease, infection, and cancer.

IgG subclass deficiency
Immunoglobulins (Ig) are glycoprotein molecules that function as antibodies. Since antibodies are present in the bloodstream or bound to cell membranes, they are considered part of the humoral immune system. The humoral system is mediated by secreted antibodies.

Hypersensitivity vasculitis
Hypersensitivity vasculitis, also known as leukocytoclastic vasculitis (LCV), is a hypersensitivity reaction to a drug or foreign agent that causes inflammation and damage to blood vessels. The condition occurs when the body produces antibodies against a foreign substance, which is usually a drug. Complexes of these antibodies are then deposited in the blood vessel walls, which causes symptoms such as fever, rash and arthritis to appear.

Human leukocyte antigens
Human leukocyte antigens (HLA) are proteins that are present on the outer surface of nearly every cell in the body.

Urticaria (hives) - from Natural Standard
Urticaria, also known as hives, is characterized by red, raised itchy welts (wheals) of varying sizes on the surface of the skin. The small bumps may look similar to mosquito bites, and they tend to occur in clusters. Hives are among the most common symptoms of an allergic reaction.

Toll-like receptors
Toll-like receptors (TLRs) are proteins on the outside of certain cells that identify and help destroy disease-causing organisms (called pathogens) that have entered the body. They are present in areas of the body that are frequently exposed to outside substances such as the skin, nose, eyes, mouth, or gastrointestinal tract.

Food allergy
A food allergy occurs when an individual's immune system mistakes a food protein for a foreign substance. The immune cells overreact to substances that are normally harmless. During the allergic reaction, the body releases chemicals that trigger symptoms that can than affect the eyes, nose, and throat, as well as the skin and the lungs. Even a trace amount of the allergen can cause a reaction in sensitive individuals.

Eosinophilia
An eosinophil is a type of white blood cell that is produced in the bone marrow. These cells, which are normally found in the bloodstream and gastrointestinal tract, produce proteins that help the body fight against infections from parasitic organisms like hookworms.

Drug allergy
Drug allergies occur when the body's immune system overreacts to substances in certain medications. These substances, called allergens, are normally harmless in individuals who do not have allergies.

Cytokines
Cytokines, also called chemical messengers, are a group of proteins that help regulate the immune system. They facilitate communication among immune cells, which fight against harmful substances, such as bacteria, that enter the body.

Cryoglobulinemia
Cryoglobulinemia is a medical condition that is caused by abnormal immunoglobulins (blood proteins), called cryoglobulins. Cryoglobulin literally means "cold antibody in the blood." Cryoglobulins are either single or mixed immunoglobulins that clump together at temperatures lower than 37 degrees Celsius. This process is reversed when they are warmed.

Cockroach allergy
Cockroach allergies occur when an individual's immune system overreacts to proteins in the feces, saliva, and/or body of a cockroach.

Multiple chemical sensitivity (MCS)
Multiple chemical sensitivity (MCS) describes an allergy-like reaction or sensitivity to chemicals. Patients who have MCS experience symptoms, including headache, skin rash, dizziness, and nausea, after exposure to chemicals that most healthy individuals can tolerate. Symptoms may develop after exposure to chemicals from products, such as perfumes, gasoline, smoke, or chlorine.

Atopic dermatitis
Dermatitis literally means "inflammation of the skin." There are several different forms of dermatitis.

Antihistamines
Antihistamines, also called H1 blockers, are medicines that help alleviate allergy symptoms such as itchy eyes, sneezing, runny nose, and occasional itchy rashes (especially hives).

Angioedema
Angioedema refers to the swelling that occurs in the tissue just below the skin. Angioedema is similar to urticaria (hives), except it occurs deeper in the skin. The swellings, known as welts, usually appear around the eyes and mouth. They may also be present on the hands, feet and throat. Angioedema can develop in anywhere from a few minutes to a few hours.

Allergy skin test
A skin test is used to determine whether a patient is allergic to certain substances, such as mold, dust mites or animal dander. Patients who experience common allergy symptoms, such as sneezing, hives, watery eyes, runny nose and itching are often tested to determine specific allergies.

Allergies
An allergy, or hypersensitivity reaction, occurs when the body's immune system overreacts to a substance that is normally harmless (allergen), such as mold, pollen, animal dander or dust mites. The white blood cells of an allergic individual produce an antibody called immunoglobulin E (IgE), which attaches to the allergen. This triggers the release of histamine and other inflammatory chemicals that cause allergic symptoms, such as runny nose, watery eyes and hives.

Stevens-Johnson syndrome
Stevens-Johnson syndrome (SJS) is a type of allergic reaction that usually occurs in response to medications. It is a severe type of erythema multiforme, which is a skin disease characterized by skin eruptions and blisters. SJS is a less severe form of another disease called toxic epidermal necrolysis (TENS).

Semen allergy
Although rare, there have been reports of semen allergy, also called sperm allergy, in both men and women. This occurs when the body's immune system overreacts when it encounters semen. The white blood cells mistakenly identify proteins in the semen as harmful invaders (such as bacteria or viruses) and launch an attack against it.

Pollen allergy
Researchers estimate that pollen from flowering plants and grasses causes seasonal allergies in 35 million Americans.

Nickel allergy
Nickel allergy occurs when the body's immune system overreacts to substances in nickel. Nickel is a hard, bright, silver-white metal that is found in soil. This metal is a common component of silver coins, belt buckles, jewelry, and many other everyday items.

Mold allergy
An allergy, or hypersensitivity reaction, occurs when the body's immune system overreacts to a substance that is normally harmless (allergen), such as mold, pollen, animal dander or dust mites. The white blood cells of an allergic individual produce an antibody called immunoglobulin E (IgE), which attaches to the allergen. This triggers the release of histamine and other inflammatory chemicals that cause allergic symptoms, such as runny nose, watery eyes and hives.

Latex allergy
Latex allergy occurs when the body's immune system overreacts to proteins found in natural rubber latex. These proteins, also called allergens, are most often found in certain types of rubber gloves and latex condoms.

Insect sting allergy
An allergic reaction to an insect sting occurs when the immune system overreacts to the insect's venom. The leukocytes (white blood cells) of an allergic individual produce an antibody called immunoglobulin E (IgE), which attaches to the protein in the venom. This triggers the release of histamine and other chemicals that cause allergic symptoms, which often include redness, swelling and itching at the site of the sting.

Immunoglobulin
Immunoglobulins (Ig) are glycoprotein molecules that function as antibodies. Since antibodies are present in the bloodstream or bound to cell membranes, they are considered to be a part of the humoral immune system.

Primary immune deficiency treatment
Immune deficiencies occur when an individual's ability to fight infectious disease is compromised or entirely absent. Patients who suffer from immune deficiencies experience recurrent infections, such as sinusitis and pneumonia.

Newborn immune system
A baby's immune system is not fully developed until he/she is about six months-old. In the meantime, pregnant mothers pass immunoglobulin antibodies from their bloodstream, through the placenta, and to the fetus. These antibodies are an essential part of the fetus's immune system. They identify and bind to harmful substances, such as bacteria, viruses, and fungi that enter the body. This triggers other immune cells to destroy the foreign substance.

Selective immunoglobulin A deficiency
Selective immunoglobulin A (IgA) deficiency is a primary immune deficiency that occurs when individuals are unable to produce antibodies called immunoglobulin A.

Hypersensitivity pneumonitis
Pneumonitis is a general term for inflammation of lung tissue.

Vaccine allergy
Patients receive vaccines to prevent infections and diseases from developing. Although rare, some patients may develop allergic reactions to vaccines. This may occur when an individual is allergic to one or more products contained in the vaccine. Most allergic reactions occur if the vaccine contains antibiotics, egg proteins, gelatin, or mercury.

Transient hypogammaglobulinemia of infancy
An antibody (immunoglobulin) is an immune system protein that helps fight against infection and disease. The term "hypogammaglobulinemia" refers specifically to a low level of IgG, which is the most common antibody in the bloodstream. Additional types of antibodies, including immunoglobulin A (IgA) also may be low in children with transient hypogammaglobulinemia of infancy (THI).

Sun allergy (photosensitivity)
Sun allergy, also called photosensitivity, occurs when the body's immune system overreacts to sunlight exposure. Patients who are allergic to sunlight typically develop an itchy red rash on areas of the skin that were exposed to light. In rare cases, some patients may develop hives or blisters.