Allergic diseases are a global health problem that remain underdiagnosed and often are not adequately treated. Allergic rhinitis and urticaria, in particular, are examples of bothersome conditions that can markedly impair the quality of life of affected individuals through negative effects on sleep, social activities (including sport and leisure), ability to work, and school performance. These diseases cannot be cured at the present time, but current first-line treatments such as the highly effective nonsedating second-generation anti-histamines can markedly reduce symptoms while at the same time improving the patient's well-being. They achieve these benefits through simultaneous inhibition of two or more chemical mediators involved in the inmune-allergic cascade and this suggests that they have advantages (rapid and prolonged action, once-daily administration, greater convenience, and better tolerability/safety and efficacy) over first-generation antihistamines.