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AT-A-GLANCE
Urticaria is defined as a skin disorder characterized by local transient skin or mucosal edema (wheal) and an area of redness (erythema) that typically accompany itchy sensations and diminish within 1 day.
Symptoms may occur either spontaneously (spontaneous or idiopathic urticaria) or in response to specific stimuli, such as physical stimuli or sweating (the increase of body core temperature).
Mast cells and their histamine being released either spontaneously or in response to various stimuli play a crucial role in the pathogenicity of urticaria.
Spontaneous or idiopathic urticaria is the subtype of urticaria that most patients experience.
Autoantibodies against immunoglobulin (Ig) E or the high-affinity IgE receptor (FcεRI) that activate mast cells and basophils and induce histamine release may be detected in up to half of patients with chronic spontaneous or idiopathic urticaria (type II autoimmunity).
A certain population of patients may develop angioedema mediated by bradykinin rather than histamine.
Infections, stress, fatigue, and drugs, especially nonsteroidal antiinflammatory drugs and angiotensin-converting enzyme inhibitors, may cause or aggravate urticaria or angioedema.
However, the mechanism of mast cell activation or the exacerbation of urticaria by various factors, except for exogenous antigens and autoantibodies, remains largely unknown.
Nonsedative second-generation antihistamines are the mainstay of pharmaceutical therapy.
Omalizumab, anti-IgE antibody, or immunosuppressive medications may be taken for the treatment of urticaria and angioedema that is refractory to antihistamines even at high doses.
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Urticaria is defined as a skin disorder characterized by local transient skin or mucosal edema (wheal) and an area of redness (erythema) that typically accompany itchy sensations and diminish within a day. Angioedema is a local and transient skin or mucosal edema that develops in deep tissues mostly without itching but may accompany pain or burning sensations. Both wheals and angioedema may develop together in one patient, but either one may develop exclusively in individual patients. Whereas the term urticaria is used as an entity of disease, angioedema may mean either disease or eruption. Either wheals and angioedema or both may appear as a symptom of other disease entities, such as anaphylaxis (either wheals or angioedema), autoinflammatory syndromes (wheals), mastocytosis (wheals known as Darier sign) or hereditary angioedema (HAE; angioedema). The international guidelines advocated by the European Academy of Allergy and Clinical Immunology (EAACI)/Global Allergy and Asthma European Network (GA2LEN)/European Dermatology Forum (EDF)/World Allergy Organization (WAO) (EAACI guideline) define urticaria as a disease characterized by the development of wheals (hives), angioedema, or both and distinguishes urticaria from medical conditions in which wheals, angioedema, or both can occur as a symptom, such as a skin prick test, anaphylaxis, autoinflammatory syndromes, or HAE (bradykinin-mediated angioedema).1
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HISTORICAL PERSPECTIVE
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The school of Hippocrates first described the association of urticaria with nettles and insect bites.2 Stinging nettle (Urtica dioica) contains histamine-, serotonin-, and acetylcholine-containing fluids inside the spicules and ...