View source for Hives

{{short description|Skin disease characterized by red, raised, and itchy bumps}}
{{distinguish|HIV/AIDS}}
{{other uses|Hive (disambiguation)}}
{{Redirect|Nettle rash| information specific to stings from nettles|Urtica dioica#Stings}}
{{Infobox medical condition (new)
| name = Hives
| synonyms = Urticaria
| image = EMminor2010.JPG
| caption = Hives on the arm
| field = [[Dermatology]], [[Immunology#Clinical immunology|Clinical immunology]], Allergology
| symptoms = Red, raised, itchy bumps<ref name=NIH2016/>
| complications =
| onset =
| duration = A few days<ref name=NIH2016/>
| types =
| causes = Stress, following an infection, result of an [[allergic reaction]]<ref name=Jaf2015/>
| risks = [[Hay fever]], [[asthma]]<ref name=Zub2010/>
| diagnosis = Based on symptoms, [[patch test]]ing<ref name=Jaf2015/>
| differential =
| prevention =
| treatment = [[Antihistamine]]s, [[corticosteroid]]s, [[leukotriene inhibitors]]<ref name=Jaf2015/>
| medication =
| prognosis =
| frequency = ~20%<ref name=Jaf2015/>
| deaths =
}}
<!-- Definition and symptoms -->

'''Hives''', also known as '''urticaria''', is a kind of [[skin rash]] with red or flesh-colored, raised, itchy bumps.<ref name="NIH2016">{{Cite web |title=Hives |url=https://medlineplus.gov/hives.html |url-status=live |archive-url=https://web.archive.org/web/20160819090751/https://medlineplus.gov/hives.html |archive-date=19 August 2016 |access-date=10 August 2016}}</ref> Hives may burn or sting.<ref name="Jaf2015" /> The patches of rash may appear on different body parts,<ref name="Jaf2015" /> with variable duration from minutes to days, and typically do not leave any long-lasting skin change.<ref name="Jaf2015" /> Fewer than 5% of cases last for more than six weeks (a condition known as chronic urticaria).<ref name="Jaf2015" /> The condition frequently recurs.<ref name="Jaf2015">{{Cite journal |last1=Jafilan |first1=L |last2=James |first2=C |date=December 2015 |title=Urticaria and Allergy-Mediated Conditions. |journal=Primary Care |volume=42 |issue=4 |pages=473–83 |doi=10.1016/j.pop.2015.08.002 |pmid=26612369}}</ref><ref name="Lang 2022">{{Cite journal |last=Lang |first=David M. |date=1 September 2022 |title=Chronic Urticaria |journal=New England Journal of Medicine |volume=387 |issue=9 |pages=824–831 |doi=10.1056/NEJMra2120166 |pmid=36053507 |s2cid=251992431}}</ref>

<!-- Cause and diagnosis -->
Hives frequently occur following an infection or as a result of an [[Allergy|allergic reaction]] such as to medication, [[insect bite]]s, or food.<ref name=Jaf2015/> [[Psychological stress]], cold temperature, or vibration may also be a trigger.<ref name=NIH2016/><ref name=Jaf2015/> In half of cases the [[idiopathy|cause remains unknown]].<ref name=Jaf2015/> Risk factors include having conditions such as [[hay fever]] or [[asthma]].<ref name="Zub2010">{{Cite book |last1=Zuberbier |first1=Torsten |url=https://books.google.com/books?id=kzWdXE4VsfsC&pg=PA38 |title=Urticaria and Angioedema |last2=Grattan |first2=Clive |last3=Maurer |first3=Marcus |date=2010 |publisher=Springer Science & Business Media |isbn=978-3-540-79048-8 |page=38 |language=en |archive-url=https://web.archive.org/web/20160821084717/https://books.google.ca/books?id=kzWdXE4VsfsC&pg=PA38 |archive-date=2016-08-21 |url-status=live}}</ref> Diagnosis is typically based on appearance.<ref name=Jaf2015/> [[Patch test]]ing may be useful to determine the allergy.<ref name=Jaf2015/>

<!-- Prevention and treatment -->
Prevention is by avoiding whatever it is that causes the condition.<ref name=Jaf2015/> Treatment is typically with [[antihistamine]]s, with the second generation antihistamines such as [[fexofenadine]], [[loratadine]] and [[cetirizine]] being preferred due to less risk of sedation and cognitive impairment.<ref name="Lang 2022" /> In refractory (obstinate) cases, [[corticosteroid]]s or [[leukotriene inhibitors]] may also be used.<ref name=Jaf2015/> Keeping the environmental temperature cool is also useful.<ref name=Jaf2015/> For cases that last more than six weeks, long-term antihistamine therapy is indicated. [[Immunosuppressant]]s such as [[omalizumab]] or [[cyclosporin]] may also be used.<ref name="Lang 2022" />

<!-- Epidemiology and culture -->
About 20% of people are affected at some point in their lives.<ref name=Jaf2015/> Short duration cases occur equally in males and females, lasting a few days and without leaving any long-lasting skin changes.<ref name=Jaf2015/> Long duration cases are more common in females.<ref name=Gri2016/> Short duration cases are also more common among children, while long duration cases are more common among those who are middle-aged.<ref name=Gri2016/> Hives have been described since at least the time of [[Hippocrates]].<ref name="Gri2016">{{Cite book |last1=Griffiths |first1=Christopher |url=https://books.google.com/books?id=EyypCwAAQBAJ&pg=SA42-PA3 |title=Rook's Textbook of Dermatology, 4 Volume Set |last2=Barker |first2=Jonathan |last3=Bleiker |first3=Tanya |last4=Chalmers |first4=Robert |last5=Creamer |first5=Daniel |date=2016 |publisher=John Wiley & Sons |isbn=978-1-118-44117-6 |edition=9 |page=Chapter 42.3 |language=en}}</ref> The term urticaria is from the [[Latin]] ''urtica'' meaning "[[Urtica dioica|nettle]]".<ref name="A Dictionary of Entomology">{{Cite book |url=https://books.google.com/books?id=9IcmCeAjp6cC&pg=PA1430 |title=A Dictionary of Entomology |date=2011 |publisher=CABI |isbn=978-1-84593-542-9 |page=1430 |language=en |archive-url=https://web.archive.org/web/20160821091615/https://books.google.ca/books?id=9IcmCeAjp6cC&pg=PA1430 |archive-date=2016-08-21 |url-status=live}}</ref>
{{TOC limit}}

==Signs and symptoms==
[[File:Hives2010.JPG|thumb|Hives on the left chest wall. They are slightly raised.]] [[File:Hives2018.png|thumb|Hives]]
[[File:Urticaria.png|thumb|Drawing of hives]]
Hives, or urticaria, is a form of [[skin rash]] with red, raised, itchy bumps.<ref name=NIH2016/> They may also burn or sting.<ref name=Jaf2015/> Hives can appear anywhere on the surface of the skin. Whether the trigger is allergic or not, a complex release of inflammatory mediators, including [[histamine]] from cutaneous [[mast cells]], results in fluid leakage from superficial blood vessels. Hives may be pinpoint in size or several inches in diameter, they can be individual or confluent, coalescing into larger forms.<ref name="Lang 2022" />

[[Angioedema]] is a related condition (also from allergic and nonallergic causes), though fluid leakage is from much deeper blood vessels in the subcutaneous or submucosal layers. Individual hives that are painful, last more than 24 hours, or leave a bruise as they heal are more likely to be a more serious condition called [[urticarial vasculitis]]. Hives caused by stroking the skin (often linear in appearance) are due to a benign condition called [[dermatographic urticaria]].{{cn|date=January 2025}}

==Cause==
Hives can also be classified by the purported causative agent. Many different substances in the environment may cause hives, including medications, food and physical agents. In perhaps more than 50% of people with chronic hives of unknown cause, it is due to an [[autoimmune]] reaction.<ref name="FraserRobertson2013">{{Cite journal |vauthors=Fraser K, Robertson L |date=Dec 2013 |title=Chronic urticaria and autoimmunity |url=http://www.skintherapyletter.com/2013/18.7/2.html |url-status=live |journal=Skin Therapy Lett |type=Review |volume=18 |issue=7 |pages=5–9 |pmid=24305753 |archive-url=https://web.archive.org/web/20160131141235/http://www.skintherapyletter.com/2013/18.7/2.html |archive-date=2016-01-31}}</ref> Risk factors include having conditions such as [[hay fever]] or [[asthma]].<ref name=Zub2010/>

===Medications===
Drugs that have caused allergic reactions evidenced as hives include [[codeine]], sulphate of [[morphia]], [[dextroamphetamine]],<ref name="dxl57">{{Cite web |date=June 2006 |title=Prescribing Information Dexedrine |url=http://dailymed.nlm.nih.gov/dailymed/fdaDrugXsl.cfm?id=1215&type=display |archive-url=https://archive.today/20121213204801/http://dailymed.nlm.nih.gov/dailymed/fdaDrugXsl.cfm?id=1215&type=display |archive-date=December 13, 2012 |publisher=GlaxoSmithKline}}</ref> [[aspirin]], [[ibuprofen]], [[penicillin]], [[clotrimazole]], trichazole, [[sulfonamide (medicine)|sulfonamide]]s, [[anticonvulsant]]s, [[cefaclor]], [[piracetam]], [[vaccine]]s, and [[antidiabetic drug]]s. The antidiabetic [[sulphonylurea]] [[glimepiride]], in particular, has been documented to induce allergic reactions manifesting as hives.{{citation needed|date=June 2020}}

===Food===
The most common food allergies in adults are [[shellfish]] and [[Nut (fruit)|nut]]s. The most common food allergies in children are [[shellfish]], nuts, [[egg (food)|eggs]], [[wheat]], and [[soy]]. One study showed [[Balsam of Peru]], which is in many processed foods, to be the most common cause of immediate contact urticaria.<ref>{{Cite book |last=Alexander A. Fisher |url=https://books.google.com/books?id=dQBAzfyCeQ8C&q=%22balsam+of+peru%22+hives&pg=PA635 |title=Fisher's Contact Dermatitis |date=2008 |publisher=PMPH-USA |isbn=978-1-55009-378-0 |access-date=2014-04-24 |archive-url=https://web.archive.org/web/20140705062725/http://books.google.com/books?id=dQBAzfyCeQ8C&pg=PA635&dq=%22balsam+of+peru%22+hives&hl=en&sa=X&ei=dGJZU5u6LYjJsATvnoHACw&ved=0CEgQ6AEwAQ#v=onepage&q=%22balsam%20of%20peru%22%20hives&f=false |archive-date=2014-07-05 |url-status=live}}</ref>  Another food allergy that can cause hives is [[alpha-gal allergy]], which may cause sensitivity to milk and red meat. A less common cause is exposure to certain bacteria, such as ''[[Streptococcus]]'' species or possibly ''[[Helicobacter pylori]]''.<ref name="pmid8601663">{{Cite journal |last1=Tebbe |first1=Beate |last2=Geilen |first2=Christoph C. |last3=Schulzke |first3=Jörg-Dieter |last4=Bojarski |first4=Christian |last5=Radenhausen |first5=Michael |last6=Orfanos |first6=Constantin E. |year=1996 |title=Helicobacter pylori infection and chronic urticaria |journal=Journal of the American Academy of Dermatology |volume=34 |issue=4 |pages=685–6 |doi=10.1016/S0190-9622(96)80086-7 |pmid=8601663}}</ref>

===Infection or environmental agent===
{{expand section|date=April 2024}}
Hives including chronic spontaneous hives, can be a complication and symptom of a parasitic infection, such as [[blastocystosis]] and [[strongyloidiasis]] among others.<ref name="pmid26648083">{{Cite journal |last1=Kolkhir |first1=P. |last2=Balakirski |first2=G. |last3=Merk |first3=HF. |last4=Olisova |first4=O. |last5=Maurer |first5=M. |date=December 2015 |title=Chronic spontaneous urticaria and internal parasites – a systematic review. |journal=Allergy |volume=71 |issue=3 |pages=308–322 |doi=10.1111/all.12818 |pmid=26648083 |doi-access=free}}</ref>

The rash that develops from [[poison ivy]], [[poison oak]], and [[poison sumac]] contact is commonly mistaken for urticaria. This rash is caused by contact with [[urushiol]] and results in a form of [[contact dermatitis]] called [[urushiol-induced contact dermatitis]]. Urushiol is spread by contact but can be washed off with a strong grease- or oil-dissolving detergent and cool water and rubbing ointments.{{cn|date=January 2025}}

===Dermatographic urticaria===
{{Main|Dermatographic urticaria}}
[[Dermatographic urticaria]] (also known as dermatographism or "skin writing") is marked by the appearance of weals or welts on the skin as a result of scratching or firm stroking of the skin. Seen in 4–5% of the population, it is one of the most common types of urticaria,<ref>{{Cite journal |last1=Jedele |first1=Kerry B. |last2=Michels |first2=Virginia V. |year=1991 |title=Familial dermographism |journal=American Journal of Medical Genetics |volume=39 |issue=2 |pages=201–3 |doi=10.1002/ajmg.1320390216 |pmid=2063925}}</ref> in which the skin becomes raised and inflamed when stroked, scratched, rubbed, and sometimes even slapped.<ref>{{Cite journal |last1=Kontou-Fili |first1=K. |last2=Borici-Mazi |first2=R. |last3=Kapp |first3=A. |author-link3=Alexander Kapp (dermatologist and allergist) |last4=Matjevic |first4=L. J. |last5=Mitchel |first5=F. B. |year=1997 |title=Physical urticaria: Classification and diagnostic guidelines |journal=Allergy |volume=52 |issue=5 |pages=504–13 |doi=10.1111/j.1398-9995.1997.tb02593.x |pmid=9201361 |s2cid=45982469}}</ref>

The skin reaction usually becomes evident soon after the scratching and disappears within 30 minutes. Dermatographism is the most common form of a subset of chronic hives, acknowledged as "physical hives".{{citation needed|date=August 2013}}

It stands in contrast to the linear reddening that does not itch seen in healthy people who are scratched. In most cases, the cause is unknown, although it may be preceded by a viral infection, antibiotic therapy, or emotional upset. Dermatographism is diagnosed by applying pressure by stroking or scratching the skin.<ref>{{Cite journal |last1=Bhute |first1=Dipti |last2=Doshi |first2=Bhavana |last3=Pande |first3=Sushil |last4=Mahajan |first4=Sunanda |last5=Kharkar |first5=Vidya |date=March 2008 |title=Dermatographism |journal=Indian Journal of Dermatology, Venereology and Leprology |volume=74 |issue=2 |pages=177–179 |doi=10.4103/0378-6323.39724 |pmid=18388395 |id={{Gale|A177631349}} |doi-access=free}}</ref> The hives should develop within a few minutes. Unless the skin is highly sensitive and reacts continually, treatment is not needed. Taking antihistamines can reduce the response in cases that are annoying to the person.{{citation needed|date=August 2013}}

===Pressure or delayed pressure===
This type of hives can occur right away, precisely after a pressure stimulus or as a deferred response to sustained pressure being enforced to the skin. In the deferred form, the hives only appear after about six hours from the initial application of pressure to the skin. Under normal circumstances, these hives are not the same as those witnessed with most urticaria. Instead, the protrusion in the affected areas is typically more spread out. The hives may last from eight hours to three days. The source of the pressure on the skin can happen from tight fitted clothing, belts, clothing with tough straps, walking, leaning against an object, standing, sitting on a hard surface, etc. The areas of the body most commonly affected are the hands, feet, trunk, abdomen, buttocks, legs and face. Although this appears to be very similar to dermatographism, the cardinal difference is that the swelled skin areas do not become visible quickly and tend to last much longer. This form of the skin disease is, however, rare.{{citation needed|date=August 2013}}

===Cholinergic or stress===
{{Main|Cholinergic urticaria}}

[[Cholinergic urticaria]] (CU) is one of the [[physical urticaria]] which is provoked during sweating events such as exercise, bathing, staying in a heated environment, or emotional stress. The hives produced are typically smaller than classic hives and are generally shorter-lasting.<ref name="CU2009REF2">{{Cite journal |last1=Moore-Robinson |first1=Miriam |last2=Warin |first2=Robert P. |year=1968 |title=Some Clikical Aspects of Cholhstergic Urticaria |journal=British Journal of Dermatology |volume=80 |issue=12 |pages=794–9 |doi=10.1111/j.1365-2133.1968.tb11948.x |pmid=5706797 |s2cid=58415911}}</ref><ref name="CU2009REF3">{{Cite journal |last1=Hirschmann |first1=J. V. |last2=Lawlor |first2=F |last3=English |first3=JS |last4=Louback |first4=JB |last5=Winkelmann |first5=RK |last6=Greaves |first6=MW |year=1987 |title=Cholinergic Urticaria - A Clinical and Histologic Study |journal=Archives of Dermatology |volume=123 |issue=4 |pages=462–7 |doi=10.1001/archderm.1987.01660280064024 |pmid=3827277}}</ref>

Multiple subtypes have been elucidated, each of which require distinct treatment.<ref name="PCU">{{Cite journal |last1=Nakamizo |first1=S. |last2=Egawa |first2=G. |last3=Miyachi |first3=Y. |last4=Kabashima |first4=K. |year=2012 |title=Cholinergic urticaria: Pathogenesis-based categorization and its treatment options |url=https://zenodo.org/record/891804 |journal=Journal of the European Academy of Dermatology and Venereology |volume=26 |issue=1 |pages=114–6 |doi=10.1111/j.1468-3083.2011.04017.x |pmid=21371134 |s2cid=35802279 |doi-access=free}}</ref><ref name="PCU2012">{{Cite journal |last1=Bito |first1=Toshinori |last2=Sawada |first2=Yu |last3=Tokura |first3=Yoshiki |year=2012 |title=Pathogenesis of Cholinergic Urticaria in Relation to Sweating |journal=Allergology International |volume=61 |issue=4 |pages=539–44 |doi=10.2332/allergolint.12-RAI-0485 |pmid=23093795 |doi-access=free}}</ref>

===Cold-induced===
{{Further|Cold urticaria}}
The cold type of urticaria is caused by exposure of the skin to extreme cold, damp and windy conditions; it occurs in two forms. The rare form is hereditary and becomes evident as hives all over the body 9 to 18 hours after cold exposure. The common form of cold urticaria demonstrates itself with the rapid onset of hives on the face, neck, or hands after exposure to cold. Cold urticaria is common and lasts for an average of five to six years. The population most affected is young adults, between 18 and 25 years old. Many people with the condition also have dermographism and cholinergic hives.{{citation needed|date=August 2013}}

Severe reactions can be seen with exposure to cold water; swimming in cold water is the most common cause of a severe reaction. This can cause a massive discharge of histamine, resulting in low blood pressure, fainting, shock and even loss of life. Cold urticaria is diagnosed by dabbing an ice cube against the skin of the forearm for 1 to 5 minutes. A distinct hive should develop if a person has cold urticaria. This is different from the normal redness that can be seen in people without cold urticaria. People with cold urticaria need to learn to protect themselves from a hasty drop in body temperature. Regular antihistamines are not generally efficacious. One particular antihistamine, cyproheptadine (Periactin), has been found to be useful. The tricyclic antidepressant [[doxepin]] has been found to be effective blocking agents of histamine. Finally, a medication named ketotifen, which keeps mast cells from discharging histamine, has also been employed with widespread success.{{citation needed|date=August 2013}}

===Solar urticaria===
{{Main|Solar urticaria}}

This form of the disease occurs on areas of the skin exposed to the sun; the condition becomes evident within minutes of exposure.{{Citation needed|date=September 2016}}

===Water-induced===
{{Main|Aquagenic urticaria}}
This type of urticaria is also termed rare and occurs upon contact with water. The response is not temperature-dependent and the skin appears similar to the cholinergic form of the disease. The appearance of hives is within one to 15 minutes of contact with the water and can last from 10 minutes to two hours. This kind of hives does not seem to be stimulated by histamine discharge like the other physical hives. Most researchers believe this condition is actually skin sensitivity to additives in the water, such as chlorine. Water urticaria is diagnosed by dabbing tap water and distilled water to the skin and observing the gradual response. Aquagenic urticaria is treated with capsaicin (Zostrix) administered to the chafed skin. This is the same treatment used for [[shingles]]. Antihistamines are of questionable benefit in this instance since histamine is not the causative factor.{{citation needed|date=August 2013}}

===Exercise===
The condition was first distinguished in 1980. People with exercise urticaria (EU) experience hives, itchiness, shortness of breath and low blood pressure five to 30 minutes after beginning exercise. These symptoms can progress to shock and even sudden death. Jogging is the most common exercise to cause EU, but it is not induced by a hot shower, fever, or with fretfulness. This differentiates EU from cholinergic urticaria.{{citation needed|date=August 2013}}

EU sometimes occurs only when someone exercises within 30 minutes of eating particular foods, such as wheat or shellfish. For these individuals, exercising alone or eating the injuring food without exercising produces no symptoms. EU can be diagnosed by having the person exercise and then observing the symptoms. This method must be used with caution and only with the appropriate resuscitative measures at hand. EU can be differentiated from cholinergic urticaria by the hot water immersion test. In this test, the person is immersed in water at 43&nbsp;°C (109.4&nbsp;°F). Someone with EU will not develop hives, while a person with cholinergic urticaria will develop the characteristic small hives, especially on the neck and chest.{{citation needed|date=August 2013}}

The immediate symptoms of this type are treated with antihistamines, [[epinephrine]] and airway support. Taking antihistamines prior to exercise may be effective. [[Ketotifen]] is acknowledged to stabilise mast cells and prevent histamine release, and has been effective in treating this hives disorder. Avoiding exercise or foods that cause the mentioned symptoms is very important. In particular circumstances, tolerance can be brought on by regular exercise, but this must be under medical supervision.{{citation needed|date=August 2013}}

==Pathophysiology==
{{See also|List of human leukocyte antigen alleles associated with cutaneous conditions}}
The skin lesions of urticarial disease are caused by an inflammatory reaction in the skin, causing leakage of capillaries in the [[dermis]], and resulting in an [[edema]] which persists until the [[interstitial fluid]] is absorbed into the surrounding cells.{{citation needed|date=August 2013}}

Hives are caused by the release of [[histamine]] and other mediators of inflammation ([[cytokines]]) from cells in the skin. This process can be the result of an allergic or nonallergic reaction, differing in the eliciting mechanism of histamine release.<ref>{{Cite book |title=Pathophysiology: the biologic basis for disease in adults and children |date=2014 |publisher=Elsevier – Health Sciences Division |isbn=978-0-323-08854-1 |editor-last=Kathryn L. McCance |edition=Seventh |editor-last2=Sue E. Huether |editor-last3=Valentina L. Brashers |editor-last4=Neal S. Rote}}{{pn|date=October 2024}}</ref>

===Allergic hives===
Histamine and other proinflammatory substances are released from [[mast cells]] in the skin and tissues in response to the binding of [[allergen]]-bound [[IgE]] antibodies to high-affinity cell surface receptors. Basophils and other inflammatory cells are also seen to release histamine and other mediators, and are thought to play an important role, especially in chronic urticarial diseases.{{cn|date=January 2025}}

===Autoimmune hives===
{{Main|Autoimmune urticaria}}
Over half of all cases of chronic [[idiopathic]] hives are the result of an autoimmune trigger. Roughly 50% of people with chronic urticaria spontaneously develop autoantibodies directed at the receptor [[FcεRI]] located on skin mast cells. Chronic stimulation of this receptor leads to chronic hives. People with hives often have other autoimmune conditions, such as [[autoimmune thyroiditis]], [[celiac disease]], [[type 1 diabetes]], [[rheumatoid arthritis]], [[Sjögren's syndrome]] or [[systemic lupus erythematosus]].<ref name="FraserRobertson2013" />

===Infections===
Hive-like rashes commonly accompany viral illnesses, such as the common cold. They usually appear three to five days after the cold has started, and may even appear a few days after the cold has resolved.{{cn|date=January 2025}}

===Nonallergic hives===
Mechanisms other than allergen-antibody interactions are known to cause histamine release from mast cells. Many drugs, for example [[morphine]], can induce direct histamine release not involving any [[immunoglobulin]] molecule. Also, a diverse group of signaling substances called [[neuropeptides]], have been found to be involved in emotionally induced hives. Dominantly inherited cutaneous and neurocutaneous [[porphyrias]] ([[porphyria cutanea tarda]], [[hereditary coproporphyria]], [[variegate porphyria]] and [[erythropoietic protoporphyria]]) have been associated with [[solar urticaria]]. The occurrence of drug-induced solar urticaria may be associated with porphyrias. This may be caused by IgG binding, not IgE.{{cn|date=January 2025}}

===Dietary histamine poisoning===
This is termed [[scombroid food poisoning]]. Ingestion of free histamine released by bacterial decay in fish flesh may result in a rapid-onset, allergic-type symptom complex which includes hives. However, the hives produced by scombroid is reported not to include wheals.<ref>{{Cite web |date=2011-07-01 |title=Scombroid fish poisoning. DermNet NZ |url=http://dermnetnz.org/reactions/scombroid.html |url-status=live |archive-url=https://web.archive.org/web/20120204041343/http://dermnetnz.org/reactions/scombroid.html |archive-date=2012-02-04 |access-date=2012-02-25 |publisher=Dermnetnz.org}}</ref>

===Stress and chronic idiopathic hives===
Chronic idiopathic hives has been anecdotally linked to [[stress (biological)|stress]] since the 1940s.<ref>{{Cite journal |last1=Mitchell |first1=John H |last2=Curran |first2=Charles A |last3=Myers |first3=Ruth N |year=1947 |title=Some Psychosomatic Aspects of Allergic Diseases |journal=Psychosomatic Medicine |volume=9 |issue=3 |pages=184–91 |doi=10.1097/00006842-194705000-00003 |pmid=20239792}}</ref> A large body of evidence demonstrates an association between this condition and both poor emotional well-being<ref>{{Cite journal |last1=Uguz |first1=Faruk |last2=Engin |first2=Burhan |last3=Yilmaz |first3=Ertan |year=2008 |title=Axis I and Axis II diagnoses in patients with chronic idiopathic urticaria |journal=Journal of Psychosomatic Research |volume=64 |issue=2 |pages=225–9 |doi=10.1016/j.jpsychores.2007.08.006 |pmid=18222137}}</ref> and reduced health-related [[quality of life]].<ref>{{Cite journal |last1=Engin |first1=B |last2=Uguz |first2=F |last3=Yilmaz |first3=E |last4=Ozdemir |first4=M |last5=Mevlitoglu |first5=I |year=2007 |title=The levels of depression, anxiety and quality of life in patients with chronic idiopathic urticaria |journal=Journal of the European Academy of Dermatology and Venereology |volume=22 |issue=1 |pages=36–40 |doi=10.1111/j.1468-3083.2007.02324.x |pmid=18181971 |s2cid=24060839}}</ref> A link between stress and this condition has also been shown.<ref>{{Cite journal |last1=Yang |first1=Hsiao-Yu |last2=Sun |first2=Chee-Ching |last3=Wu |first3=Yin-Chang |last4=Wang |first4=Jung-Der |year=2005 |title=Stress, Insomnia, and Chronic Idiopathic Urticaria – a Case-Control Study |url=http://ntur.lib.ntu.edu.tw/handle/246246/93579 |url-status=live |journal=Journal of the Formosan Medical Association |volume=104 |issue=4 |pages=254–63 |pmid=15909063 |archive-url=https://web.archive.org/web/20170908204623/http://ntur.lib.ntu.edu.tw/handle/246246/93579 |archive-date=2017-09-08}}</ref> Some cases have been thought to be due to stress, including an association between [[post-traumatic stress]] and chronic idiopathic hives.<ref>{{Cite journal |last1=Chung |first1=Man Cheung |last2=Symons |first2=Christine |last3=Gilliam |first3=Jane |last4=Kaminski |first4=Edward R. |year=2010 |title=The relationship between posttraumatic stress disorder, psychiatric comorbidity, and personality traits among patients with chronic idiopathic urticaria |journal=Comprehensive Psychiatry |volume=51 |issue=1 |pages=55–63 |doi=10.1016/j.comppsych.2009.02.005 |pmid=19932827}}</ref><ref>{{Cite journal |last1=Chung |first1=Man Cheung |last2=Symons |first2=Christine |last3=Gilliam |first3=Jane |last4=Kaminski |first4=Edward R. |year=2010 |title=Stress, psychiatric co-morbidity and coping in patients with chronic idiopathic urticaria |journal=Psychology & Health |volume=25 |issue=4 |pages=477–90 |doi=10.1080/08870440802530780 |pmid=20204926 |s2cid=44740560}}</ref> In most cases of [[Chronic spontaneous urticaria|chronic idiopathic urticaria]], no cause is identified.<ref name="Lang 2022" />

==Diagnosis==
[[File:Micrograph of urticaria.jpg|thumb|[[Micrograph]] of urticaria. Dermal edema [solid arrows in (A, B)] and a sparse superficial predominantly perivascular and interstitial infiltrate of lymphocytes and eosinophils without signs of vasculitis (dashed arrow).<ref>{{Cite journal |last1=Giang |first1=Jenny |last2=Seelen |first2=Marc A. J. |last3=van Doorn |first3=Martijn B. A. |last4=Rissmann |first4=Robert |last5=Prens |first5=Errol P. |last6=Damman |first6=Jeffrey |year=2018 |title=Complement Activation in Inflammatory Skin Diseases |journal=Frontiers in Immunology |volume=9 |article-number=639 |doi=10.3389/fimmu.2018.00639 |issn=1664-3224 |pmc=5911619 |pmid=29713318 |doi-access=free}}</ref>]]
Diagnosis is typically based on the appearance.<ref name=Jaf2015/> The cause of chronic hives can rarely be determined.<ref name="AAAAIfive">{{Cite web |title=Five Things Physicians and Patients Should Question |url=http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_AAAAI.pdf |url-status=live |archive-url=https://web.archive.org/web/20121103151124/http://choosingwisely.org/wp-content/uploads/2012/04/5things_12_factsheet_AAAAI.pdf |archive-date=November 3, 2012 |access-date=August 14, 2012 |website=Choosing Wisely |publisher=[[American Academy of Allergy, Asthma, and Immunology]]}}</ref> [[Patch test]]ing may be useful to determine the allergy.<ref name=Jaf2015/> In some cases regular extensive [[allergy test]]ing over a long period of time is requested in hopes of getting new insight.<ref name="manageurticaria">{{Cite journal |last1=Tarbox |first1=James A. |last2=Gutta |first2=Ravi C. |last3=Radojicic |first3=Cristine |last4=Lang |first4=David M. |year=2011 |title=Utility of routine laboratory testing in management of chronic urticaria/angioedema |journal=Annals of Allergy, Asthma & Immunology |volume=107 |issue=3 |pages=239–43 |doi=10.1016/j.anai.2011.06.008 |pmid=21875543}}</ref><ref name="testurticaria">{{Cite journal |last1=Kozel |first1=Martina M.A. |last2=Bossuyt |first2=Patrick M.M. |last3=Mekkes |first3=Jan R. |last4=Bos |first4=Jan D. |year=2003 |title=Laboratory tests and identified diagnoses in patients with physical and chronic urticaria and angioedema: A systematic review |journal=Journal of the American Academy of Dermatology |volume=48 |issue=3 |pages=409–16 |doi=10.1067/mjd.2003.142 |pmid=12637921}}</ref> No evidence shows regular allergy testing results in identification of a problem or relief for people with chronic hives.<ref name="manageurticaria" /><ref name="testurticaria" /> Regular allergy testing for people with chronic hives is not recommended.<ref name="AAAAIfive" />

===Acute versus chronic===
* {{Visible anchor|Acute}} urticaria is defined as the presence of [[Evanescent (dermatology)|evanescent]] [[wheals]] which completely resolve within six weeks.<ref name="Andrews p150">{{Cite book |last1=James |first1=William |url=https://archive.org/details/andrewsdiseasess00mdwi_659 |title=Andrews' Diseases of the Skin: Clinical Dermatology |last2=Berger |first2=Timothy |last3=Elston |first3=Dirk |publisher=Saunders |year=2005 |isbn=978-0-7216-2921-6 |edition=10th |page=[https://archive.org/details/andrewsdiseasess00mdwi_659/page/n160 150] |url-access=limited}}</ref> Acute urticaria becomes evident a few minutes after the person has been exposed to an allergen. The outbreak may last several weeks, but usually the hives are gone in six weeks. Typically, the hives are a reaction to food, but in about half the cases, the trigger is unknown. Common foods may be the cause, as well as bee or wasp stings, or skin contact with certain fragrances. Acute viral infection is another common cause of acute urticaria (viral [[exanthem]]). Less common causes of hives include friction, pressure, temperature extremes, exercise, and sunlight.{{cn|date=January 2025}}
* {{Visible anchor|Chronic}} urticaria is defined as the presence of hives which persist for greater than six weeks.<ref name="Andrews p150" /> Some of the more severe chronic cases have lasted more than 20 years. A survey indicated chronic urticaria lasted a year or more in more than 50% of those affected and 20 years or more in 20% of them.<ref name="pmid5801331">{{Cite journal |last1=Champion |first1=R. H. |last2=Roberts |first2=S. O. B. |last3=Carpenter |first3=R. G. |last4=Roger |first4=J. H. |year=1969 |title=Urticaria and Angio-Oedema |journal=British Journal of Dermatology |volume=81 |issue=8 |pages=588–97 |doi=10.1111/j.1365-2133.1969.tb16041.x |pmid=5801331 |s2cid=41089623}}</ref> Provocative skin challenge testing may be done in those with chronic urticaria, in which the skin is exposed to pressure ([[dermatographic urticaria|dermatographisim]]), cold temperatures, warm temperatures, or light in an attempt to provoke symptoms and aid in the diagnosis.<ref name="Lang 2022" /> The history of physical examination guide the diagnosis of chronic urticaria, with extensive lab testing not recommended.<ref name="Lang 2022" /><ref name="Shaker 2020">{{Cite journal |last1=Shaker |first1=Marcus |last2=Oppenheimer |first2=John |last3=Wallace |first3=Dana |last4=Lang |first4=David M. |last5=Rambasek |first5=Todd |last6=Dykewicz |first6=Mark |last7=Greenhawt |first7=Matthew |date=July 2020 |title=Optimizing Value in the Evaluation of Chronic Spontaneous Urticaria: A Cost-Effectiveness Analysis |journal=The Journal of Allergy and Clinical Immunology: In Practice |volume=8 |issue=7 |pages=2360–2369.e1 |doi=10.1016/j.jaip.2019.11.004 |pmid=31751758 |s2cid=208229213}}</ref>

Acute and chronic hives are visually indistinguishable on visual inspection alone.{{cn|date=January 2025}}

===Related conditions===
====Angioedema====
[[Angioedema]] is similar to hives,<ref>{{DorlandsDict|one/000004995|angioedema}}</ref> but in angioedema, the swelling occurs in a lower layer of the dermis than in hives,<ref>{{Cite web |date=2006-03-01 |title=Hives (Urticaria and Angioedema) |work=WebMD |url=http://www.webmd.com/allergies/guide/hives-urticaria-angioedema |url-status=live |archive-url=https://web.archive.org/web/20070824182301/http://www.webmd.com/allergies/guide/hives-urticaria-angioedema |archive-date=2007-08-24 |access-date=2007-08-24}}</ref> as well as in the subcutis. This swelling can occur around the mouth, eyes, in the throat, in the abdomen, or in other locations. Hives and angioedema sometimes occur together in response to an [[allergen]], and is a concern in severe cases, as angioedema of the throat can be fatal.{{cn|date=January 2025}}

====Vibratory angioedema====
This very rare form of angioedema develops in response to contact with vibration. In vibratory angioedema, symptoms develop within two to five minutes after contact with a vibrating object and abate after about an hour. People with this disorder do not experience dermographism or pressure urticaria. Vibratory angioedema is diagnosed by holding a vibrating device such as a laboratory vortex machine against the forearm for four minutes. Speedy swelling of the whole forearm extending into the upper arm is also noted later. The principal treatment is avoidance of vibratory stimulants. Antihistamines have also been proven helpful.{{citation needed|date=August 2013}}

==Management==
The mainstay of therapy for both acute and chronic hives is education, avoiding triggers and using antihistamines.{{cn|date=January 2025}}

Chronic hives can be difficult to treat and lead to significant disability. Unlike the acute form, 50–80% of people with chronic hives have no identifiable triggers. But 50% of people with chronic hives will experience remission within 1 year.<ref>{{Cite journal |vauthors=Kozel MM, Mekkes JR, Bossuyt PM, Bos JD |year=2001 |title=Natural course of physical and chronic urticaria and angioedema in 220 patients |journal=J Am Acad Dermatol |volume=45 |issue=3 |pages=387–391 |doi=10.1067/mjd.2001.116217 |pmid=11511835}}</ref> Overall, treatment is geared towards symptomatic management. Individuals with chronic hives may need other medications in addition to antihistamines to control symptoms. People who experience hives with angioedema require emergency treatment as this is a life-threatening condition.{{cn|date=January 2025}}

Treatment guidelines for the management of chronic hives have been published.<ref>{{Cite journal |last=Maurer |first=M |date=2013 |title=Revisions to the international guidelines on the diagnosis and therapy of chronic urticaria |journal=J Dtsch Dermatol Ges |volume=11 |issue=10 |pages=971–978 |doi=10.1111/ddg.12194 |pmid=24034140 |s2cid=22110680 |doi-access=free}}</ref><ref>{{Cite journal |last=Bernstein |first=J |date=2014 |title=The diagnosis and management of acute and chronic urticaria: 2014 update. |journal=J Allergy Clin Immunol |volume=133 |issue=5 |pages=1270–1277.e66 |doi=10.1016/j.jaci.2014.02.036 |pmid=24766875 |doi-access=free}}</ref> According to the 2014 American practice parameters, treatment involves a stepwise approach. Step 1 consists of second generation, H1 receptor blocking antihistamines. Systemic glucocorticoids can also be used for episodes of severe disease but should not be used for long term due to their long list of side effects. Step 2 consists of increasing the dose of the current antihistamine, adding other antihistamines, or adding a leukotriene receptor antagonist such as montelukast. Step 3 consists of adding or replacing the current treatment with hydroxyzine or doxepin. If the individual doesn't respond to steps 1–3 then they are considered to have refractory symptoms. At this point, anti-inflammatory medications (dapsone, sulfasalazine), immunosuppressants (cyclosporin, sirolimus) or other medications like [[omalizumab]] can be used. These options are explained in more detail below.{{cn|date=January 2025}}

First generation antihistamines, such as [[diphenhydramine]] or [[hydroxyzine]], are not recommended as a first line therapy as they block both brain and peripheral H1 receptors, causing sedation. [[H1 antagonist#Second-generation and third-generation (selective)|Second-generation antihistamines]], such as [[loratadine]], [[cetirizine]], [[fexofenadine]] or [[desloratadine]], selectively antagonize peripheral H1 receptors, and are less sedating, less [[anticholinergic]], and generally preferred over the first-generation antihistamines.<ref name="Zuberbier2012">{{Cite journal |last=Zuberbier |first=T |date=January 2012 |title=A Summary of the New International EAACI/GA2LEN/EDF/WAO Guidelines in Urticaria. |journal=The World Allergy Organization Journal |volume=5 |issue=Suppl 1 |pages=S1-5 |doi=10.1097/WOX.0b013e3181f13432 |pmc=3488932 |pmid=23282889 |doi-access=free}}</ref><ref>{{Cite journal |last1=Sharma |first1=M |last2=Bennett |first2=C |last3=Cohen |first3=SN |last4=Carter |first4=B |date=14 November 2014 |title=H1-antihistamines for chronic spontaneous urticaria. |journal=Cochrane Database of Systematic Reviews |volume=2017 |issue=11 |article-number=CD006137 |doi=10.1002/14651858.CD006137.pub2 |pmc=6481497 |pmid=25397904}}</ref> Fexofenadine, a new-generation antihistamine that blocks histamine H1 receptors, may be less sedating than some second-generation antihistamines.<ref name="Huang">{{Cite journal |last1=Huang |first1=Cheng-zhi |last2=Jiang |first2=Zhi-hui |last3=Wang |first3=Jian |last4=Luo |first4=Yue |last5=Peng |first5=Hua |date=29 November 2019 |title=Antihistamine effects and safety of fexofenadine: a systematic review and meta-analysis of randomized controlled trials |journal=BMC Pharmacology and Toxicology |volume=20 |issue=1 |page=72 |doi=10.1186/s40360-019-0363-1 |issn=2050-6511 |pmc=6884918 |pmid=31783781 |doi-access=free}}</ref>

People who do not respond to the maximum dose of H1 antihistamines may benefit from increasing the dose further, then to switching to another non-sedating antihistamine, then to adding a [[leukotriene antagonist]], then to using an older antihistamine, then to using systemic steroids and finally to using [[ciclosporin]] or [[omalizumab]].<ref name=Zuberbier2012/> Steroids are often associated with rebound hives once discontinued.<ref name="Lang 2022" />

[[H2-receptor antagonists]] are sometimes used in addition to H1-antagonists to treat urticaria, but there is limited evidence for their efficacy.<ref>{{Cite journal |last1=Fedorowicz |first1=Zbys |last2=van Zuuren |first2=Esther J |last3=Hu |first3=Nianfang |date=14 March 2012 |title=Histamine H2-receptor antagonists for urticaria |journal=Cochrane Database of Systematic Reviews |volume=2015 |issue=2 |article-number=CD008596 |doi=10.1002/14651858.CD008596.pub2 |pmc=7390502 |pmid=22419335}}</ref>

===Systemic steroids===
Oral glucocorticoids are effective in controlling symptoms of chronic hives. However, they have an extensive list of adverse effects, such as adrenal suppression, weight gain, osteoporosis, hyperglycemia, etc. Therefore, their use should be limited to a couple of weeks. In addition, one study found that systemic glucocorticoids combined with antihistamines did not hasten the time to symptom control compared with antihistamines alone.<ref>{{Cite journal |vauthors=Kim S, Baek S, Shin B, Yoon SY, Park SY, Lee T, Lee YS, Bae YJ, Kwon HS, Cho YS, Moon HB, Kim TB |year=2013 |title=Influence of initial treatment modality on long-term control of chronic idiopathic urticaria |journal=PLOS ONE |volume=8 |issue=7 |article-number=e69345 |bibcode=2013PLoSO...869345K |doi=10.1371/journal.pone.0069345 |pmc=3720657 |pmid=23935990 |doi-access=free}}</ref>

===Leukotriene-receptor antagonists===
Leukotrienes are released from mast cells along with histamine. The medications, montelukast and zafirlukast, inhibit leukotriene effects, and may be useful as add-on treatment or in isolation for people with CU.<ref name=rayner/> A 2024 review found that montelukast and zafirlukast, when used in addition to H1 antihistamines, have a small effect in reducing urticaria with no significant [[adverse effect]]s.<ref name="rayner">{{Cite journal |last1=Rayner |first1=Daniel G. |last2=Liu |first2=Ming |last3=Chu |first3=Alexandro W.L. |last4=Chu |first4=Xiajing |last5=Guyatt |first5=Gordon H. |last6=Oykhman |first6=Paul |last7=Cao |first7=Daniel J. |last8=Moellman |first8=Joseph |last9=Ben-Shoshan |first9=Moshe |last10=Baker |first10=Diane R. |last11=Waserman |first11=Susan |last12=Lang |first12=David |last13=Sheikh |first13=Javed |last14=Mathur |first14=Sameer K. |last15=Beck |first15=Lisa A.|display-authors=3 |date=2024-10-01 |title=Leukotriene receptor antagonists as add-on therapy to antihistamines for urticaria: Systematic review and meta-analysis of randomized clinical trials |url=https://linkinghub.elsevier.com/retrieve/pii/S0091674924005712 |journal=Journal of Allergy and Clinical Immunology |language=en |volume=154 |issue=4 |pages=996–1007 |doi=10.1016/j.jaci.2024.05.026|pmid=38852861 |url-access=subscription }}</ref>

===Other===
Other options for refractory symptoms of chronic hives include anti-inflammatory medications, omalizumab, and immunosuppressants.
Potential anti-inflammatory agents include dapsone, sulfasalazine, and hydroxychloroquine.  Dapsone is a sulfone antimicrobial agent and is thought to suppress prostaglandin and leukotriene activity. It is helpful in therapy-refractory cases<ref>{{Cite journal |vauthors=Boehm I, etal |date=Jul 1999 |title=Urticaria treated with dapsone |journal=Allergy |volume=54 |issue=7 |pages=765–6 |doi=10.1034/j.1398-9995.1999.00187.x |pmid=10442538 |s2cid=40767363}}</ref> and is contraindicated in people with G6PD deficiency. Sulfasalazine, a 5-ASA derivative, is thought to alter adenosine release and inhibit IgE mediated mast cell degranulation, Sulfasalazine is a good option for people with anemia who cannot take dapsone. Hydroxychloroquine is an antimalarial agent that suppresses T lymphocytes. It has a low cost however it takes longer than dapsone or sulfasalazine to work.{{cn|date=January 2025}}

[[Omalizumab]] was approved by the FDA in 2014 for people with hives 12 years old and above with chronic hives. It is a monoclonal antibody directed against IgE. Significant improvement in pruritus and quality of life was observed in a phase III, multicenter, randomized control trial.<ref>{{Cite journal |last1=Maurer |first1=Marcus |last2=Rosén |first2=Karin |last3=Hsieh |first3=Hsin-Ju |last4=Saini |first4=Sarbjit |last5=Grattan |first5=Clive |last6=Gimenéz-Arnau |first6=Ana |last7=Agarwal |first7=Sunil |last8=Doyle |first8=Ramona |last9=Canvin |first9=Janice |last10=Kaplan |first10=Allen |last11=Casale |first11=Thomas |year=2013 |title=Omalizumab for the Treatment of Chronic Idiopathic or Spontaneous Urticaria |journal=New England Journal of Medicine |volume=368 |issue=10 |pages=924–35 |doi=10.1056/NEJMoa1215372 |pmid=23432142 |doi-access=free}}</ref>

Immunosuppressants used for CU include cyclosporine, tacrolimus, sirolimus, and mycophenolate. Calcineurin inhibitors, such as cyclosporine and tacrolimus, inhibit cell responsiveness to mast cell products and inhibit T cell activity. They are preferred by some experts to treat severe symptoms.<ref>{{Cite journal |last=Kaplan AP |year=2009 |title=What the first 10,000 patients with chronic urticaria have taught me: a personal journey |journal=J Allergy Clin Immunol |volume=123 |issue=3 |pages=713–717 |doi=10.1016/j.jaci.2008.10.050 |pmid=19081615 |doi-access=free}}</ref> Sirolimus and mycophenolate have less evidence for their use in the treatment of chronic hives but reports have shown them to be efficacious.<ref>{{Cite journal |last=Morgan M |year=2009 |title=Treatment of refractory chronic urticaria with sirolimus |journal=Arch Dermatol |volume=145 |issue=6 |pages=637–9 |doi=10.1001/archdermatol.2009.13 |pmid=19528416}}</ref><ref>{{Cite journal |vauthors=AU Shahar E, Bergman R, Guttman-Yassky E, Pollack S |year=2006 |title=Treatment of severe chronic idiopathic urticaria with oral mycophenolate mofetil in patients not responding to antihistamines and/or corticosteroids |journal=Int J Dermatol |volume=45 |issue=10 |pages=1224–1227 |doi=10.1111/j.1365-4632.2006.02655.x |pmid=17040448 |s2cid=19744425}}</ref> Immunosuppressants are generally reserved as the last line of therapy for severe cases due to their potential for serious adverse effects.{{cn|date=January 2025}}

A 2025 systematic review and network meta-analysis found that among patients with chronic hives that were inadequately controlled with antihistamines, omalizumab and [[remibrutinib]] were among the most effective, while [[Ciclosporin|cyclosporine]] may be among the most harmful.<ref>{{Cite journal |last1=Chu |first1=Alexandro W. L. |last2=Oykhman |first2=Paul |last3=Chu |first3=Xiajing |last4=Rayner |first4=Daniel G. |last5=Bhangal |first5=Sukhdeep |last6=Dam |first6=Andrew |last7=Xu |first7=Janice |last8=Sheikh |first8=Javed |last9=Trayes |first9=Kathryn P. |last10=Frazier |first10=Winfred T. |last11=Lang |first11=David M. |last12=Beck |first12=Lisa A. |last13=Mathur |first13=Sameer K. |last14=Waserman |first14=Susan |last15=Thabane |first15=Lehana |date=2025-10-01 |title=Comparative efficacy and safety of biologics and systemic immunomodulatory treatments for chronic urticaria: Systematic review and network meta-analysis |url=https://www.jacionline.org/article/S0091-6749(25)00646-3/fulltext |journal=Journal of Allergy and Clinical Immunology |language=English |volume=156 |issue=4 |pages=1008–1023 |doi=10.1016/j.jaci.2025.06.004 |issn=0091-6749 |pmid=40663028|doi-access=free }}</ref>

==Prognosis==
In those with chronic urticaria, defined as either continuous or intermittent symptoms lasting longer than 6 weeks, 35% of people are symptom free 1 year after treatment, while 29% have a reduction in their symptoms.<ref name="Lang 2022" /> Those with a longer disease duration typically have a worse prognosis, with greater symptom severity.<ref name="Lang 2022" /> Chronic urticaria is often accompanied by an intense pruritus, and other symptoms associated with a reduced quality of life and a high burden of co-morbid psychiatric conditions such as anxiety and depression.<ref name="Lang 2022" /><ref name="Tat 2019">{{Cite journal |last=Tat |first=Tugba Songul |date=4 January 2019 |title=Higher Levels of Depression and Anxiety in Patients with Chronic Urticaria |journal=Medical Science Monitor |volume=25 |pages=115–120 |doi=10.12659/MSM.912362 |pmc=6329254 |pmid=30609422}}</ref> The prevalence of depressive symptoms, anxiety symptoms, and sleep disturbances in patients with chronic urticaria has been estimated to be 37%, 46%, and 53%, respectively.<ref>{{Cite journal |last1=Rayner |first1=Daniel G. |last2=Gou |first2=David |last3=Weiler |first3=Laura |last4=Irelewuyi |first4=Lola |last5=Xiong |first5=Grace |last6=Wang |first6=Elaine |last7=Sivanesanathan |first7=Tresha |title=Prevalence of Mental Health Symptoms in Chronic Urticaria: A Systematic Review and Meta-Analysis |journal=Allergy |date=2025 |article-number=all.16482 |language=en |volume=80 |issue=8 |doi=10.1111/all.16482 |pmid=39873233 |pmc=12368746 |issn=1398-9995|doi-access=free }}</ref>

==Epidemiology==
Chronic urticaria is usually seen in those older than 40 years, it is more common in women.<ref name="Lang 2022" /> The prevalence of chronic urticaria is 0.23% in the United States.<ref name="Lang 2022" /> Notable risk factors associated with an increased risk of chronic urticaria include allergic rhinitis, asthma, atopic dermatitis, and autoimmune thyroid disorders.<ref>{{Cite journal |last1=Gou |first1=David |last2=Kalo |first2=Carmen |last3=Grignano |first3=Veronica |last4=Grover |first4=Krystal |last5=Rayner |first5=Daniel G. |date=2025-01-31 |title=Risk Factors for Chronic Urticaria: A Systematic Review and Meta-Analysis |url=https://journals.sagepub.com/doi/10.1177/12034754251316300 |journal=Journal of Cutaneous Medicine and Surgery |volume=29 |issue=4 |pages=404–405 |language=en |doi=10.1177/12034754251316300 |pmid=39887056 |issn=1203-4754|url-access=subscription }}</ref>

==Research==
[[Afamelanotide]] is being studied as a hives treatment.<ref>{{Cite journal |last1=Langan |first1=EA |last2=Nie, Z |last3=Rhodes, LE |date=Sep 2010 |title=Melanotropic peptides: more than just 'Barbie drugs' and 'sun-tan jabs'? |journal=The British Journal of Dermatology |volume=163 |issue=3 |pages=451–5 |doi=10.1111/j.1365-2133.2010.09891.x |pmid=20545686 |s2cid=8203334}}</ref>

[[Opioid antagonists]] such as [[naltrexone]] have tentative evidence to support their use.<ref>{{Cite journal |last1=Phan |first1=NQ |last2=Bernhard |first2=JD |last3=Luger |first3=TA |last4=Ständer |first4=S |date=October 2010 |title=Antipruritic treatment with systemic μ-opioid receptor antagonists: a review. |journal=Journal of the American Academy of Dermatology |volume=63 |issue=4 |pages=680–8 |doi=10.1016/j.jaad.2009.08.052 |pmid=20462660}}</ref>

==History==
The term ''urticaria'' was first used by the Scottish physician [[William Cullen]] in 1769.<ref>Volcheck, Gerald W. (2009) ''Clinical Allergy Diagnosis and Management''. London: Springer.</ref> It originates from the Latin word ''urtica'', meaning stinging hair or nettle,<ref name="A Dictionary of Entomology" /> as the classical presentation follows the contact with a perennial flowering plant ''[[Urtica dioica]]''.<ref>{{Cite journal |vauthors=Poonawalla T, Kelly B |year=2009 |title=Urticaria: A review |journal=American Journal of Clinical Dermatology |volume=10 |issue=1 |pages=9–21 |doi=10.2165/0128071-200910010-00002 |pmid=19170406 |s2cid=35029156}}</ref> The history of urticaria dates back to 1000–2000 BC with its reference as a wind-type concealed rash in the book ''The Yellow Emperor's Inner Classic'' from ''[[Huangdi Neijing]]''. [[Hippocrates]] in the 4th century first described urticaria as "knidosis" after the Greek word ''knido'' for nettle.<ref>McGovern TW, Barkley TM (2000). [http://www.telemedicine.org/stamford.htm ''The electronic textbook of Dermatology'']. New York: Internet Dermatology Society.</ref> The discovery of [[mast cell]]s by [[Paul Ehrlich]] in 1879 brought urticaria and similar conditions under a comprehensive idea of allergic conditions.<ref>Juhlin L. (2000) ''The History of Urticaria and Angioedema''. Department of Dermatology, University Hospital, Uppsala, Sweden. ESHDV Special Annual Lecture.</ref>

==See also==
* [[Urticarial vasculitis]]
* [[Dermatitis]]

==References==
{{Reflist}}

==External links==
{{Commons category}}
* [http://www.dermnet.com/moduleIndex.cfm?moduleID=19 Urticaria photo library at Dermnet] {{Webarchive|url=https://web.archive.org/web/20070925113447/http://www.dermnet.com/moduleIndex.cfm?moduleID=19 |date=2007-09-25 }}

{{Medical resources
| DiseasesDB     = 13606
| ICD10          = {{ICD10|L|50| |l|50}}
| ICD9           = {{ICD9|708}}
| ICDO           =
| OMIM           =
| MedlinePlus    = 000845
| eMedicineSubj  = search
| eMedicineTopic = Urticaria
| MeshID         = D014581
}}
{{Diseases of the skin and appendages by morphology}}
{{Urticaria and erythema}}
{{Hypersensitivity and autoimmune diseases}}
{{Authority control}}

[[Category:Wikipedia medicine articles ready to translate]]
[[Category:Wikipedia emergency medicine articles ready to translate]]
[[Category:Skin conditions resulting from errors in metabolism]]
[[Category:Type I hypersensitivity]]
[[Category:Urticaria and angioedema|Urticaria and angioedema]]