Antipruritic
Encyclopedia
Antipruritics, also known as anti-itch drugs, are medication
s that inhibit the itch
ing (Latin: pruritus) that is often associated with sunburn
s, allergic reactions, eczema
, psoriasis
, chickenpox
, fungal infections, insect bites and stings like those from mosquito
es, flea
s, and mite
s, and contact dermatitis
and urticaria
caused by plants such as poison ivy
(urushiol-induced contact dermatitis
) or stinging nettle
.
antipruritics in the form of cream
s and spray
s are often available over-the-counter. Oral
anti-itch drugs also exist and are usually prescription drug
s. The active ingredient
s usually belong to the following classes:
Medication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
s that inhibit the itch
Itch
Itch is a sensation that causes the desire or reflex to scratch. Itch has resisted many attempts to classify it as any one type of sensory experience. Modern science has shown that itch has many similarities to pain, and while both are unpleasant sensory experiences, their behavioral response...
ing (Latin: pruritus) that is often associated with sunburn
Sunburn
A sunburn is a burn to living tissue, such as skin, which is produced by overexposure to ultraviolet radiation, commonly from the sun's rays. Usual mild symptoms in humans and other animals include red or reddish skin that is hot to the touch, general fatigue, and mild dizziness. An excess of UV...
s, allergic reactions, eczema
Eczema
Eczema is a form of dermatitis, or inflammation of the epidermis . In England, an estimated 5.7 million or about one in every nine people have been diagnosed with the disease by a clinician at some point in their lives.The term eczema is broadly applied to a range of persistent skin conditions...
, psoriasis
Psoriasis
Psoriasis is an autoimmune disease that appears on the skin. It occurs when the immune system mistakes the skin cells as a pathogen, and sends out faulty signals that speed up the growth cycle of skin cells. Psoriasis is not contagious. However, psoriasis has been linked to an increased risk of...
, chickenpox
Chickenpox
Chickenpox or chicken pox is a highly contagious illness caused by primary infection with varicella zoster virus . It usually starts with vesicular skin rash mainly on the body and head rather than at the periphery and becomes itchy, raw pockmarks, which mostly heal without scarring...
, fungal infections, insect bites and stings like those from mosquito
Mosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
es, flea
Flea
Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...
s, and mite
Mite
Mites, along with ticks, are small arthropods belonging to the subclass Acari and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology.-Diversity and systematics:...
s, and contact dermatitis
Contact dermatitis
Contact dermatitis is a term for a skin reaction resulting from exposure to allergens or irritants . Phototoxic dermatitis occurs when the allergen or irritant is activated by sunlight....
and urticaria
Urticaria
Urticaria is a kind of skin rash notable for pale red, raised, itchy bumps. Hives is frequently caused by allergic reactions; however, there are many non-allergic causes...
caused by plants such as poison ivy
Poison ivy
Toxicodendron radicans, better known as poison ivy , is a poisonous North American plant that is well known for its production of urushiol, a clear liquid compound found within the sap of the plant that causes an itching rash in most people who touch it...
(urushiol-induced contact dermatitis
Urushiol-induced contact dermatitis
Urushiol-induced contact dermatitis is the medical name given to allergic rashes produced by the oil urushiol, which is contained in various plants, including the plants of the genus Toxicodendron , other plants in the family Anacardiaceae Urushiol-induced contact dermatitis (also called...
) or stinging nettle
Stinging nettle
Stinging nettle or common nettle, Urtica dioica, is a herbaceous perennial flowering plant, native to Europe, Asia, northern Africa, and North America, and is the best-known member of the nettle genus Urtica...
.
Common antipruritics
TopicalTopical
In medicine, a topical medication is applied to body surfaces such as the skin or mucous membranes such as the vagina, anus, throat, eyes and ears.Many topical medications are epicutaneous, meaning that they are applied directly to the skin...
antipruritics in the form of cream
Cream (pharmaceutical)
A cream is a topical preparation usually for application to the skin. Creams for application to mucus membranes such as those of the rectum or vagina are also used. Creams may be considered pharmaceutical products as even cosmetic creams are based on techniques developed by pharmacy and...
s and spray
Spray
Spray can refer to:* Spray ** Aerosol spray** Blood spray** Road/tire spray, kicked up from a vehicle tire** Snow spray, a spray that creates artificial snow fall...
s are often available over-the-counter. Oral
Mouth
The mouth is the first portion of the alimentary canal that receives food andsaliva. The oral mucosa is the mucous membrane epithelium lining the inside of the mouth....
anti-itch drugs also exist and are usually prescription drug
Prescription drug
A prescription medication is a licensed medicine that is regulated by legislation to require a medical prescription before it can be obtained. The term is used to distinguish it from over-the-counter drugs which can be obtained without a prescription...
s. The active ingredient
Active ingredient
An active ingredient is the substance of a pharmaceutical drug or a pharmaceutical ingredient and bulk active in medicine; in pesticide formulations active substance may be used. Some medications and pesticide products may contain more than one active ingredient...
s usually belong to the following classes:
- AntihistamineAntihistamineAn H1 antagonist is a histamine antagonist of the H1 receptor that serves to reduce or eliminate effects mediated by histamine, an endogenous chemical mediator released during allergic reactions...
s such as diphenhydramineDiphenhydramineDiphenhydramine hydrochloride is a first-generation antihistamine possessing anticholinergic, antitussive, antiemetic, and sedative properties which is mainly used to treat allergies. Like most other first-generation antihistamines, the drug also has a powerful hypnotic effect, and for this reason...
(Benadryl) - CorticosteroidCorticosteroidCorticosteroids are a class of steroid hormones that are produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte...
s such as hydrocortisone topical cream, see topical steroidTopical steroidTopical steroids are the topical forms of corticosteroids. Topical steroids are the most commonly prescribed topical medications for the treatment of rash, eczema, and dermatitis. Topical steroids have anti-inflammatory properties, and are classified based on their vasoconstriction abilities. There... - Local anestheticLocal anestheticA local anesthetic is a drug that causes reversible local anesthesia, generally for the aim of having local analgesic effect, that is, inducing absence of pain sensation, although other local senses are often affected as well...
s such as benzocaineBenzocaineBenzocaine is a local anesthetic commonly used as a topical pain reliever, or in cough drops. It is the active ingredient in many over-the-counter anesthetic ointments...
topical cream (Lanacaine) - CounterirritantCounterirritantA counterirritant is a substance which creates inflammation in one location with the goal of lessening the inflammation in another location. They can be used as antipruritics. This strategy falls into the more general category of counterstimulation....
s, such as mint oilMenthaMentha is a genus of flowering plants in the family Lamiaceae . The species are not clearly distinct and estimates of the number of species varies from 13 to 18. Hybridization between some of the species occurs naturally...
, mentholMentholMenthol is an organic compound made synthetically or obtained from peppermint or other mint oils. It is a waxy, crystalline substance, clear or white in color, which is solid at room temperature and melts slightly above. The main form of menthol occurring in nature is -menthol, which is assigned...
, or camphorCamphorCamphor is a waxy, white or transparent solid with a strong, aromatic odor. It is a terpenoid with the chemical formula C10H16O. It is found in wood of the camphor laurel , a large evergreen tree found in Asia and also of Dryobalanops aromatica, a giant of the Bornean forests...
Disputed and questionable antipruritics
- Burow's solutionBurow's solutionBurow's solution is a pharmacological preparation made of aluminium acetate dissolved in water. It was invented in the mid-19th century by Karl August Burow, an ophthalmologist....
(aluminium acetateAluminium acetateAluminium acetates are the aluminium salts of acetic acid. Three such salts exist:* neutral Aluminium triacetate, Al3* basic Aluminium diacetate, HOAl2* basic Aluminium monoacetate, 2AlC2H3O2-Synthesis:...
) - Olive oilOlive oilOlive oil is an oil obtained from the olive , a traditional tree crop of the Mediterranean Basin. It is commonly used in cooking, cosmetics, pharmaceuticals, and soaps and as a fuel for traditional oil lamps...
- Jewelweed, has been shown to be devoid of any anti-itch activity in several controlled studies
- SSRIsSelective serotonin reuptake inhibitorSelective serotonin re-uptake inhibitors or serotonin-specific reuptake inhibitor are a class of compounds typically used as antidepressants in the treatment of depression, anxiety disorders, and some personality disorders. The efficacy of SSRIs is disputed...
(selective serotonin reuptake inhibitors) comprise a class of medicines commonly used for depression, and are also said to be effective in controlling pruritus in a small number of refractory cases. MirtazapineMirtazapineMirtazapine is a tetracyclic antidepressant used primarily in the treatment of depression. It is also sometimes used as a hypnotic, antiemetic, and appetite stimulant, and for the treatment of anxiety, among other indications...
, a different type of antidepressantAntidepressantAn antidepressant is a psychiatric medication used to alleviate mood disorders, such as major depression and dysthymia and anxiety disorders such as social anxiety disorder. According to Gelder, Mayou &*Geddes people with a depressive illness will experience a therapeutic effect to their mood;...
, also has antipruritic effects due to its strong antagonism of the H1 receptorH1 receptorThe H1 receptor is a histamine receptor belonging to the family of Rhodopsin like G-protein-coupled receptors. This receptor, which is activated by the biogenic amine histamine, is expressed throughout the body, to be specific, in smooth muscles, on vascular endothelial cells, in the heart, and in...
. - Calamine lotion, containing zinc oxideZinc oxideZinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...
and iron(III) oxideIron(III) oxideIron oxide or ferric oxide is the inorganic compound with the formula Fe2O3. It is one of the three main oxides of iron, the other two being iron oxide , which is rare, and iron oxide , which also occurs naturally as the mineral magnetite. As the mineral known as hematite, Fe2O3 is the main...
, is a traditional remedy for mild itching, such as that typically associated with chicken pox - although the U.S. Food and Drug Administration (FDA) has asserted that it has little if any effect. - Paste of sodium bicarbonateSodium bicarbonateSodium bicarbonate or sodium hydrogen carbonate is the chemical compound with the formula Na HCO3. Sodium bicarbonate is a white solid that is crystalline but often appears as a fine powder. It has a slightly salty, alkaline taste resembling that of washing soda . The natural mineral form is...
(baking soda) and water, applied topically - Ammonium hydroxideAmmonium hydroxideAmmonia solution, also known as ammonium hydroxide, ammonia water, ammonical liquor, ammonia liquor, aqua ammonia, aqueous ammonia, or simply ammonia, is a solution of ammonia in water. It can be denoted by the symbols NH3...
(household ammonia), applied topically
Home remedies
- Cooling with ice or cold water (usually stops the itch for as long as the ice or cold water is applied)
- Slightly painful stimulation like rubbing, slapping, scratchingScratch reflexThe scratch reflex is a response to activation of sensory neurons whose peripheral terminals are located on the surface of the body. Some sensory neurons can be activated by stimulation with an external object such as a parasite on the body surface. Alternately, some sensory neurons can respond to...
, or heating based on a spinal antagonism between painPainPain is an unpleasant sensation often caused by intense or damaging stimuli such as stubbing a toe, burning a finger, putting iodine on a cut, and bumping the "funny bone."...
- and itch-processing neurons
External links
- Frontiers in pruritus research: scratching the brain for more effective itch therapy J. Clin. Invest. 116:1174-1185 (2006). DOI 10.1172/JCI28553