This is distinguished by its duration; a diagnosis of chronic urticaria is made only when wheals recur for a period of six weeks or longer.
This autoimmune disease can begin with urticarial plaques, but it is distinguished by the eventual development of large, tense bullae, which are absent in simple urticaria.
This is a specific urticarial eruption of pregnancy, distinguished by its periumbilical onset and its temporal relationship to gestation.
Also an eruption of pregnancy, this is distinguished by its onset within the abdominal striae and its primary morphology of pruritic papules and plaques.
