Urticaria

Summary Urticaria and angioedema are common and, if chronic, often persist for years with significant impact on quality of life and occupational ability. To achieve a better understanding of disease etiology and pathogenesis and to compare clinical trials, there is a clear need for cross‐specialty and international agreement of the nomenclature and diagnostic classification of urticaria and angioedema. At least in part this has been achieved by two recently published European guidelines. After the urticaria subtype is defined, potential triggers should be sought including persistent bacterial infections ( Helicobacter pylori , streptococci, staphylococci, Yersinia, parasites) pseudoallergic reactions (acetylsalicylic acid, rarely food additives) and/or autoreactive mechanisms (autologous serum test). Identified trigger factors should be avoided or eradicated, as this is the most successful therapeutic approach. Treatment of most urticaria subtypes is difficult and besides H1 antihistamines neither standardized nor evidence‐based. Low‐sedating H1 antihistamines represent the mainstay of treatment, as they have a better therapeutic index and pharmacodynamic properties than older agents. In severe cases their dose has to be increased which is off‐label use. The evidence base for treatment alternatives is totally insufficient and the risk‐benefit profile of each off‐label used drug should be carefully considered.