[Inducible urticaria and chronic spontaneous urticaria]

In the recently published 2013 revision of the guidelines of urticaria, chronic urticaria (CU) gathers chronic spontaneous urticaria (CSU) and inducible urticaria (IU), and excludes pseudourticarial rashes with more than 24h-lasting rash or more than 72h-lasting angiœdema. Activity and psychosocial impact of the disease must be measured with validated scores such as Urticaria and Angioedema Activity Scores, Urticaria Control Test, CU-Q2OL, AE-QOL. Although an allergic cause is generaly absent in CU, pathomecanisms remain elusive even since the well-known role of mast cell degranulation and the presence of autoantibodies anti-FcRεI or anti-IgE. Coagulation pathways may be involved, at least as an amplifying phenomenon. Mean duration of CU is 1 to 4 years, but many patients still have symptoms after 10 years, some predictive factors being known as severity, angioedema, a positive autologous serum test, inducible urticaria. Recommended routine diagnosic tests are validated provocation tests for IU (and cryoproteins for cold urticaria), blood cell count and CRP for CSU, since a thorough history and a normal detailed physical examination should avoid unnecessary tests. Management of CU has been improved by the off-label use of increased dosages of second generation anti- H1 antihistamines, but a subsequent therapeutic intensification may be necessary in some cases. Educational program may prevent this intensification. Independent studies evaluating available molecules are needed, along with more fundamental research studies.