Urticaria.

Urticaria has been known as a disease since antiquity. However, in the last decades an increasing understanding of the mechanisms involved in its pathogenesis has shown the high heterogeneity of different urticaria subtypes. Clear distinction of the subtypes is required not only to choose the correct measures in diagnosis and management, but also to interpret the available data in research. The subtypes can be grouped into spontaneous urticaria, which includes acute urticaria and chronic urticaria, the physical urticarias, special types of urticaria including, e.g. contact urticaria, and diseases related to urticaria for historical reasons, e.g. urticaria pigmentosa. Most urticaria subtypes have a profound impact on the quality of life and effective treatment is thus required in case the diagnostic procedures do not reveal a cause which can be treated. Although, for symptomatic relief, nonsedating H1-antihistamines are the first choice in most subtypes of urticaria, double-blind controlled studies have shown that dosages required may exceed those recommended for other diseases, e.g. allergic rhinitis. Alternative treatments should be reserved for unresponsive patients.