Urticaria 904954 225736230 2008-07-15T03:58:56Z 86.142.38.82 /* External links */ {{redirect|Hives|other uses|Hive}} {{Infobox_Disease | Name = Urticaria | Image = | Caption = | DiseasesDB = 13606 | ICD10 = {{ICD10|L|50| |l|50}} | ICD9 = {{ICD9|708}} | ICDO = | OMIM = | MedlinePlus = 000845 | eMedicineSubj = emerg | eMedicineTopic = 628 | MeshID = D014581 }} '''Urticaria''' (or '''hives''') is a skin condition, commonly caused by an allergic reaction, that is characterized by raised red skin [[wheal]]s (welts). It is also known as ''[[nettle]] rash'' or ''uredo''. Wheals from urticaria can appear anywhere on the body, including the face, lips, tongue, throat, and ears. The wheals may vary in size from about 5 mm (0.2 inches) in diameter to the size of a dinner plate; they typically [[itch]] severely, sting, or burn, and often have a pale border. Urticaria is generally caused by direct contact with an allergenic substance, or an immune response to food or some other [[allergen]], but can also appear for other reasons, notably emotional stress. The rash can be triggered by quite innocent events, such as mere rubbing or exposure to cold. ==Pathophysiology== [[Image:Urticaria 2.jpg|thumb|right|150px|Allergic urticaria on the shin induced by an antibiotic]] 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. Urticarial disease is thought to be 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 non-allergic reaction, differing in the eliciting mechanism of histamine release. [[Image:Urticaria arm.jpg|thumb|right|150px|Allergic urticaria on the arm]] ; Allergic urticaria : Histamine and other pro-inflammatory 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. ; Non-allergic urticaria : 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 urticaria. 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. ==Differential diagnosis== 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/oil dissolving detergent and cool water. ==Types== *''Acute urticaria'' usually show up a few minutes after contact with the allergen and can last a few hours to several weeks. Food allergic reactions typically fit in this category. Common causes of reaction include consumption of [[shellfish]], [[nut]]s, [[egg (food)|eggs]], [[fish]], [[acid]] derivatives, [[dye]], or a combination of these. A less common cause is exposure to certain viruses or bacteria, such as [[streptococcus]] or possibly ''[[Helicobacter pylori]]''(Tebbe B, Geilen CC, Schulzke JD, Bojarski C, Radenhausen M, Orfanos CE. Helicobacter pylori infection and chronic urticaria. J Am Acad Dermatol. Apr 1996;34(4):685-6).{{Fact|date=June 2008}} In these cases, the hives may be exacerbated by other factors, such as those listed under Physical Urticarias below. *''Chronic urticaria'' refers to hives that persists for 6 weeks or more. There are no visual differences between acute and chronic urticaria. Some of the more severe chronic cases have lasted more than 20 years. A survey indicated that chronic urticaria lasted a year or more in more than 50% of sufferers and 20 years or more in 20% of them. Of course this does mean that in almost half the people it clears up within a year and in 80% it clears up within 20 years or less.<ref name="pmid5801331">{{cite journal |author=Champion RH, Roberts SO, Carpenter RG, Roger JH |title=Urticaria and angio-oedema. A review of 554 patients |journal=Br. J. Dermatol. |volume=81 |issue=8 |pages=588–97 |year=1969 |pmid=5801331 |doi=}}</ref> *''Drug-induced urticaria'' has been known to result in severe cardiorespiratory failure. The anti-diabetic [[sulphonylurea]] [[glimepiride]] (trade name Amaryl®), in particular, has been documented to induce allergic reactions manifesting as urticaria. Other cases include [[dextroamphetamine]]<ref name=dxl57>{{cite web |title=Prescribing Information Dexedrine |date=June 2006 |url=http://dailymed.nlm.nih.gov/dailymed/fdaDrugXsl.cfm?id=1215&type=display |publisher=GlaxoSmithKline}}</ref>, [[aspirin]], [[penicillin]], [[clotrimazole]], [[sulfonamide]]s and [[anticonvulsant]]s. *''Physical urticarias'' are often categorized into the following. **[[Water urticaria|Aquagenic:]] Reaction to water (rare) **[[Cholinergic urticaria|Cholinergic]]: Reaction to body heat, such as when [[Exercise urticaria|exercising]] or after a hot shower **Cold ([[Chronic cold urticaria]]): Reaction to cold, such as ice, cold air or water **Delayed Pressure: Reaction to standing for long periods, bra-straps, elastic bands on undergarments, belts **[[Dermatographic urticaria|Dermatographic]]: Reaction when skin is scratched (very common) **Heat: Reaction to hot food or objects (rare) **Solar: Reaction to direct sunlight (rare) **Vibration: Reaction to vibration (rare) **Adrenergic: Reaction to adrenaline / noradrenaline (extremely rare) ==Related conditions== [[Angioedema]] is not related to urticaria. In angioedema, the swelling occurs in a lower layer of the dermis than it does in urticaria<ref>{{cite web | url = http://www.webmd.com/allergies/guide/hives-urticaria-angioedema | title = Hives (Urticaria and Angioedema) | date = 2006-03-01 | accessdate = 2007-08-24}}</ref>, as well as in the subcutis. This swelling can occur around the mouth, in the throat, in the abdomen, or in other locations. Urticaria 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. ==Treatment and management== Urticarias can be very difficult to treat. There are no guaranteed treatments or means of controlling attacks, and some sub-populations are treatment resistant, with medications spontaneously losing their effectiveness and requiring new medications to control attacks. It can be difficult to determine appropriate medications since some such as [[loratadine]] require a day or two to build up to effective levels, and since the condition is intermittent and outbreaks typically clear up without any treatment. Most treatment plans for urticaria involve being aware of one's triggers, but this can be difficult since there are several different forms of urticaria and people often exhibit more than one type. Also, since symptoms are often [[idiopathic]] (unknown reason) there might not be any clear trigger. If one's triggers can be identified then outbreaks can often be managed by limiting one's exposure to these situations. ===Histamine antagonists=== Drug treatment is typically in the form of [[Antihistamine]]s such as [[diphenhydramine]], [[hydroxyzine]], [[cetirizine]] and other [[histamine receptor|H<sub>1</sub> receptor]] antagonists.<ref name="pmid18094952">{{cite journal |author=Greaves MW, Tan KT |title=Chronic Urticaria: Recent Advances |journal=Clin Rev Allergy Immunol |volume=33 |issue=1-2 |pages=134–143 |year=2007 |pmid=18094952 |doi=10.1007/s12016-007-0038-3}}</ref> These are taken on a regular basis to protective effect, lessening or halting attacks. While the disease is obviously physiological in origin, psychological treatments such as [[stress management]] can sometimes lessen severity and occurrence. Additionally, methods similar to psychological pain management can be used to shift focus away from the discomfort and itchiness during an attack. The [[H2-receptor antagonist|H<sub>2</sub>-receptor antagonist]]s such as [[cimetidine]] and [[ranitidine]] may help control symptoms either [[prophylactic]]ally or by lessening symptoms during an attack.<ref name="pmid11702618">{{cite journal |author=Lee EE, Maibach HI |title=Treatment of urticaria. An evidence-based evaluation of antihistamines |journal=Am J Clin Dermatol |volume=2 |issue=1 |pages=27–32 |year=2001 |pmid=11702618 |doi=}}</ref> When taken in combination with a H<sub>1</sub> antagonist it has been shown to have a synergistic effect which is more effective than either treatment alone.{{Fact|date=December 2007}} The use of ranitidine (or other H<sub>2</sub> antagonist) for urticaria is considered an off-label use, since these drugs are primarily used for the treatment of [[peptic ulcer]] disease and [[gastroesophageal reflux]] disease. ===Other=== [[Tricyclic antidepressant]]s such as [[doxepin]], also are often potent H<sub>1</sub> and H<sub>2</sub> antagonists and may have a role in therapy, although side effects limit their use. For very severe outbreaks, an oral [[corticosteroid]] such as [[Prednisone]] is sometimes prescribed. However this form of treatment is controversial because of the extensive side effects common with corticosteroids and as such is not a recommended long-term treatment option. As of 2008 an [[Australia]]n company is performing [[clinical trial]]s with an analogue of alpha-[[melanocyte-stimulating hormone]] called [[melanotan]] (known by the [[International Nonproprietary Name]] ''afamelanotide'', formerly CUV1647)<ref name="Clinuvel-INN">{{Cite web|url=http://www.clinuvel.com/resources/pdf/asx_announcements/2008/20080617WHOGenericName.pdf|title=World Health Organisation assigns CUV1647 generic name|accessdate=2008-06-17|publisher=Clinuvel|year=2008|format=[[Portable Document Format|PDF]]}}</ref> for the treatment of solar urticaria,<ref name="Australian_Life_Scientist">{{Cite web | url = http://www.biotechnews.com.au/index.php/id;444900667 | title = Tackling skin cancer in organ transplant patients | accessdate = 2007-12-24 | publisher=Australian Life Scientist | date = 2007-04-13 | last = McDonald | first = Kate }}</ref><ref>{{cite web | url = http://www.biotechnews.com.au/index.php/id;1708412693;fp;16;fpid;1 | title = Clinuvel gets green light | accessdate = 2008-06-13 | date =2007-06-11 | publisher = Biotechnews.com.au (LifeScientist)}}</ref> a type of urticaria that develops in response to exposure to specific wavelengths of light.<ref>{{cite web | url = http://www.emedicine.com/derm/topic448.htm | title = Urticaria, Solar | accessdate = 2007-12-26 | date =2007-03-29 | last = Baron | first = ED | coauthors = Taylor, CR | publisher = [[WebMD]] }}</ref> ===Dietary=== Children with intermittent or recurrent urticaria-angiodema were fed 7 food-additives: [[tartrazine]] (E102), [[sunset yellow]] (E110), [[erythrosine]] (E127), [[annatto]] (E160b), [[sodium benzoate]] (E211), acetyl-[[salicylic acid]] (ASA) and [[aspartame]]. Reactions to the food additives were common: E110 = 64%, E160b = 60%, E211: 57%; E102 = 50%, aspartame = 48%, E127 = 35%, ASA = 12%. The authors suggest that food additive intolerance is frequent in children with recurrent or intermittent urticaria-angiodema, and that aspartame may contribute directly to urticaria-angiodema in childhood. Reference: M. de Martino et al, Food-additive intolerance and its correlation with atopy in children with recurrent or intermittent urticaria-angioedema. Pediatric Allergy and Immunology, Volume 3 Issue 1, Page 33-38, 1992. [http://www.blackwell-synergy.com/doi/abs/10.1111/j.1399-3038.1992.tb00024.x?journalCode=pai] == See also == * [[Anti-itch drug]] * [[Chronic cold urticaria]] * [[Urticaria pigmentosa]] == References == {{reflist|2}} ==External links== *[http://www.users.globalnet.co.uk/~aair/urticaria.htm Urticaria conditions and descriptions] *[http://www.emedicine.com/med/topic3014.htm eMedicine: Urticaria] *[http://www.dermnet.com/moduleIndex.cfm?moduleID=19 Urticaria photo library at Dermnet] *[http://www.wrongdiagnosis.com/h/hives/causes.htm causes] *[http://aca.ninemsn.com.au/article.aspx?id=416838 Australian television report on solar urticaria] *[http://www.patient.co.uk/showdoc/23068988 patient summary] {{Diseases of the skin and subcutaneous tissue}} [[Category:Dermatology]] [[da:Urticaria]] [[de:Nesselsucht]] [[el:Κνίδωση]] [[es:Urticaria]] [[eo:Urtikario]] [[fr:Urticaire]] [[it:Orticaria]] [[he:סרפדת]] [[lb:Nesselsucht]] [[nl:Netelroos]] [[ja:蕁麻疹]] [[pl:Pokrzywka]] [[pt:Urticária]] [[ru:Крапивница]] [[fi:Nokkosihottuma]] [[sv:Urtikaria]] [[vi:Bệnh phong ngứa]] [[tr:Ürtiker]] [[zh:荨麻疹]]