Urticaria and Angioedema: an Update on Classification and Pathogenesis

Urticaria is a common, mast cell-driven disease presenting with wheals or angioedema or both. In the last years, urticaria has increasingly attracted notice to clinicians and researchers, last but not least inspired by the approval of omalizumab, an anti-IgE antibody, for urticaria treatment. There is wide consensus on the clinical classification based on duration and elicitation. However, the pathogenesis is incompletely understood. This review summarizes current guidelines for the management and novel insights in the pathogenesis of urticaria with special focus on their impact on clinical praxis. The classification of urticaria subgroups is mainly based on clinical criteria: acute and chronic urticaria (CU). Chronic urticaria comprises both chronic spontaneous urticaria (CSU) and chronic inducible urticaria (CIndU) that includes physical and non-physical urticarias. Recent research focused on characterizing the role of cells and mediators involved in the pathogenesis of urticaria, identifying the mechanisms of mast cell activation, and investigating underlying autoimmune processes in chronic spontaneous urticarial. Currently, non-sedating antihistamines and omalizumab, an antiimmunoglobulin E antibody, are recommended for the therapy of chronic urticaria, as both exhibit a favorable efficacy and safety profile. Novel therapeutic strategies aim at specifically targeting cells and mediators involved in the pathogenesis of urticaria.