Desensitization (medicine)

Last updated
Desensitization (medicine)
ICD-9-CM 99.12
MeSH D003888
OPS-301 code 8-030

In medicine, desensitization is a method to reduce or eliminate an organism's negative reaction to a substance or stimulus.

Contents

In pharmacology, drug desensitization refers to two related concepts. First, desensitization may be equivalent to drug tolerance and refers to subjects' reactions (positive or negative) to a drug reducing following its repeated use. This is a macroscopic, organism-level effect and differs from the second meaning of desensitization, which refers to a biochemical effect where individual receptors become less responsive after repeated application of an agonist. This may be mediated by phosphorylation, for instance by beta adrenoceptor kinase at the beta adrenoceptor.

Application to allergies

For example, if a person with diabetes mellitus has a bad allergic reaction to taking a full dose of beef insulin, the person is given a very small amount of the insulin at first, so small that the person has no adverse reaction or very limited symptoms as a result. Over a period of time, larger doses are given until the person is taking the full dose. This is one way to help the body get used to the full dose, and to avoid having the allergic reaction to beef-origin insulin.

A temporary desensitization method involves the administration of small doses of an allergen to produces an IgE-mediated response in a setting where an individual can be resuscitated in the event of anaphylaxis; this approach, through uncharacterized mechanisms, eventually overrides the hypersensitive IgE response. [1]

Desensitization approaches for food allergies are generally at the research stage. They include: [2]

See also

Related Research Articles

Allergy Immune system response to a substance that most people tolerate well

Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, a runny nose, shortness of breath, or swelling. Food intolerances and food poisoning are separate conditions.

Anaphylaxis Life-threatening allergic reaction

Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. It typically causes more than one of the following: an itchy rash, throat or tongue swelling, shortness of breath, vomiting, lightheadedness, low blood pressure. These symptoms typically come on over minutes to hours.

Immunoglobulin E Immunoglobulin E (IgE) Antibody

Immunoglobulin E (IgE) is a type of antibody that has only been found in mammals. IgE is synthesised by plasma cells. Monomers of IgE consist of two heavy chains and two light chains, with the ε chain containing 4 Ig-like constant domains (Cε1-Cε4). IgE's main function is immunity to parasites such as helminths like Schistosoma mansoni, Trichinella spiralis, and Fasciola hepatica. IgE is utilized during immune defense against certain protozoan parasites such as Plasmodium falciparum. IgE may have evolved as a last line of defense to protect against venoms.

Food allergy Hypersensitivity reaction to a food

A food allergy is an abnormal immune response to food. The symptoms of the allergic reaction may range from mild to severe. They may include itchiness, swelling of the tongue, vomiting, diarrhea, hives, trouble breathing, or low blood pressure. This typically occurs within minutes to several hours of exposure. When the symptoms are severe, it is known as anaphylaxis. A food intolerance and food poisoning are separate conditions, not due to an immune response.

Type I hypersensitivity

Type I hypersensitivity is an allergic reaction provoked by re-exposure to a specific type of antigen referred to as an allergen. Type I is distinct from type II, type III and type IV hypersensitivities.

Allergic conjunctivitis

Allergic conjunctivitis (AC) is inflammation of the conjunctiva due to allergy. Although allergens differ among patients, the most common cause is hay fever. Symptoms consist of redness, edema (swelling) of the conjunctiva, itching, and increased lacrimation. If this is combined with rhinitis, the condition is termed allergic rhinoconjunctivitis (ARC).

Aspirin exacerbated respiratory disease

Aspirin exacerbated respiratory disease (AERD), also termed aspirin-induced asthma, is a medical condition initially defined as consisting of three key features: asthma, respiratory symptoms exacerbated by aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs), and nasal polyps. The symptoms of respiratory reactions in this syndrome are hypersensitivity reactions to NSAIDs rather than the typically described true allergic reactions that trigger other common allergen-induced asthma, rhinitis, or hives. The NSAID-induced reactions do not appear to involve the common mediators of true allergic reactions, immunoglobulin E or T cells. Rather, AERD is a type of NSAID-induced hypersensitivity syndrome. EAACI/WHO classifies the syndrome as one of five types of NSAID hypersensitivity or NSAID hypersensitivity reactions.

Allergen immunotherapy, also known as desensitization or hypo-sensitization, is a medical treatment for environmental allergies, such as insect bites, and asthma. Immunotherapy involves exposing people to larger and larger amounts of allergen in an attempt to change the immune system's response.

Peanut allergy

Peanut allergy is a type of food allergy to peanuts. It is different from tree nut allergies, with peanuts being legumes and not true nuts. Physical symptoms of allergic reaction can include itchiness, hives, swelling, eczema, sneezing, asthma attack, abdominal pain, drop in blood pressure, diarrhea, and cardiac arrest. Anaphylaxis may occur. Those with a history of asthma are more likely to be severely affected.

Soy allergy

Soy allergy is a type of food allergy. It is a hypersensitivity to ingesting compounds in soy, causing an overreaction of the immune system, typically with physical symptoms, such as gastrointestinal discomfort, respiratory distress, or a skin reaction. Soy is among the eight most common foods inducing allergic reactions in children and adults. It has a prevalence of about 0.3% in the general population.

Milk allergy Type of food allergy caused by milk

Milk allergy is an adverse immune reaction to one or more proteins in cow's milk. When allergy symptoms occur, they can occur rapidly or have a gradual onset. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine among other measures. The latter can take hours to days to appear, with symptoms including atopic dermatitis, inflammation of the esophagus, enteropathy involving the small intestine and proctocolitis involving the rectum and colon.

Egg allergy

Egg allergy is an immune hypersensitivity to proteins found in chicken eggs, and possibly goose, duck, or turkey eggs. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus.

Wheat allergy

Wheat allergy is an allergy to wheat which typically presents itself as a food allergy, but can also be a contact allergy resulting from occupational exposure. Like all allergies, wheat allergy involves immunoglobulin E and mast cell response. Typically the allergy is limited to the seed storage proteins of wheat. Some reactions are restricted to wheat proteins, while others can react across many varieties of seeds and other plant tissues. Wheat allergy is rare. Prevalence in adults was found to be 0.21% in a 2012 study in Japan.

Enzyme potentiated desensitization (EPD), is a treatment for allergies developed in the 1960s by Dr. Leonard M. McEwen in the United Kingdom. EPD uses much lower doses of antigens than conventional desensitization treatment paired with the enzyme β-glucuronidase. EPD is approved in the United Kingdom for the treatment of hay fever, food allergy and intolerance and environmental allergies.

A drug allergy is an allergy to a drug, most commonly a medication, and is a form of adverse drug reaction. Medical attention should be sought immediately if an allergic reaction is suspected.

Kounis syndrome is defined as acute coronary syndrome caused by an allergic reaction or a strong immune reaction to a drug or other substance. It is a rare syndrome with authentic cases reported in 130 males and 45 females, as reviewed in 2017; however, the disorder is suspected of being commonly overlooked and therefore much more prevalent. Mast cell activation and release of inflammatory cytokines as well as other inflammatory agents from the reaction leads to spasm of the arteries leading to the heart muscle or a plaque breaking free and blocking one or more of those arteries.

Alpha-gal allergy, also known as mammalian meat allergy (MMA), is a reaction to galactose-alpha-1,3-galactose (alpha-gal), whereby the body is overloaded with immunoglobulin E (IgE) antibodies on contact with the carbohydrate. Anti-gal is a human natural antibody that interacts specifically with the mammalian carbohydrate structure gal alpha 1-3Gal beta 1-4GlcNAc-R, termed, the alpha-galactosyl epitope. The alpha-gal molecule is found in all mammals except apes, humans, and Old World monkeys.

NSAID or nonsteroidal anti-inflammatory drug hypersensitivity reactions encompasses a broad range of allergic or allergic-like symptoms that occur within minutes to hours after ingesting aspirin or other NSAID nonsteroidal anti-inflammatory drugs. Hypersensitivity drug reactions differ from drug toxicity reactions in that drug toxicity reactions result from the pharmacological action of a drug, are dose-related, and can occur in any treated individual ; hypersensitivity reactions are idiosyncratic reactions to a drug. Although the term NSAID was introduced to signal a comparatively low risk of adverse effects, NSAIDs do evoke a broad range of hypersensitivity syndromes. These syndromes have recently been classified by the European Academy of Allergy and Clinical Immunology Task Force on NSAIDs Hypersensitivity.

Peanut Allergen Powder, sold under the brand name Palforzia, is an oral medication for the treatment of allergic reactions, including anaphylaxis, in children typically aged between four and 17 years of age who have confirmed cases of peanut allergy. It is taken by mouth.

Fish allergy

Fish allergy is an immune hypersensitivity to proteins found in fish. Symptoms can be either rapid or gradual in onset. The latter can take hours to days to appear. The former may include anaphylaxis, a potentially life-threatening condition which requires treatment with epinephrine. Other presentations may include atopic dermatitis or inflammation of the esophagus. Fish is one of the eight common food allergens, responsible for 90% of allergic reactions to foods: cow's milk, eggs, wheat, shellfish, peanuts, tree nuts, fish, and soy beans.

References

  1. editor, Mariana C. Castells (2011). Anaphylaxis and hypersensitivity reactions. New York: Humana Press. pp. 60–62. ISBN   978-1603279512.CS1 maint: extra text: authors list (link)
  2. Nowak-Węgrzyn A, Sampson HA (March 2011). "Future therapies for food allergies". J. Allergy Clin. Immunol. 127 (3): 558–73, quiz 574–5. doi:10.1016/j.jaci.2010.12.1098. PMC   3066474 . PMID   21277625.