21 April 2020 What is urticaria and angioedema? Urticaria Urticaria is characterized by the appearance of papules, which are skin lesions, slightly elevated due to swelling of the superficial layers of the skin. They are reddish, sometimes pale in the center. They are accompanied by itching or a burning sensation and temporarily disappear after pressure. Papules disappear without a residual injury, usually between 30 minutes to 24 hours, and may reappear. Angioedema Up to 50% of patients with urticaria may also have angioedema. Angioedema corresponds to the same swelling process but affecting the deeper layers of the skin and / or mucous membranes. It is usually more painful than itchy and its resolution is slower (up to 72 hours). Who can develop urticaria and/or angioedema? Urticaria and / or angioedema is common and can affect up to 20% of persons, any time during their life. The acute form, which lasts less than 6 weeks, is more frequent in children and young adults and is more prevalent than the chronic form, which lasts more than 6 weeks. The chronic form mainly affects adults with a predominance of females and usually resolves spontaneously in up to 6 months (50%), although it can last for years. What are the causes? The number of cases in which it is possible to identify the cause of urticaria, acute or chronic, varies widely, between 40% and 90%. Causes of acute urticaria In acute urticaria , infections are the main cause, followed by food, drugs and, more rarely, insect bites (eg, hymenoptera). Causes of chronic urticaria Chronic urticaria rarely has an allergic cause. In some cases, it can be associated with an underlying disease (autoimmune diseases, chronic infection, neoplasia) and precedes its manifestations in years. In chronic urticaria symptoms can appear without an apparent triggering factor (chronic spontaneous urticaria) or be associated with factors such as cold, pressure, increased body temperature, light, vibration, water or heat (inducible urticaria). How is it diagnosed? The clinical history and a detailed observation are essential to establish the diagnosis. Acute urticaria has a short duration and usually resolves spontaneously. It rarely requires medical test, except when an allergic cause is suspected, namely mediated by type E antibodies (IgE), which can be confirmed by skin prick tests, specific IgE tests and / or provocation test. In chronic urticaria, despite the multiplicity of possible causes, an exhaustive analytical study is not indicated. In some cases, laboratory tests or specific tests (autologous serum tests, physical agents or skin biopsy) may be required to study the underlying disease. There are diseases that present lesions like urticaria and / or angioedema but represent different clinical entities and require a specific diagnostic and therapeutic approach. Treatment of urticaria and angioedema Despite the variety of urticaria causes, treatment is essentially based on: Eliminate / avoid / treat the causal or aggravating agents (drugs, food, emotional stress), when identified; Pharmacological treatment of symptoms, which may involve drugs such as antihistamines, biological agents, immunosuppressants / immunomodulators, corticosteroids, determined individually according to the specific characteristics of the disease and the patient. In the Hospital da Luz network, you will find physician specialized in immunoallergology who make the diagnosis and guide the treatment of urticaria and / or angioedema . The authors of this text are the following allergologists from the Hospital da Luz network: Luís Miguel Borrego, Ana Morais Mendes, Ana Reis Ferreira, Andreia Ferrão, Carlos Braga, Cristina Lopes, Diana Pereira da Silva, Filipa Semedo, Isabel Costa Silva, João Gaspar Marques, Pedro Carreiro Martins, Marta Salgado, Nuno Sousa, Rosa Anita Fernandes, Susana Piedade The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
