An update on acute and chronic urticaria for the primary care provider.

Urticaria is a common dermatologic condition seen by primary care physicians. Urticaria can result in significant morbidity and a dramatic decline in quality of life. Acute urticaria is mostly an allergic or IgE-mediated reaction and tends to be self-limited, while chronic urticaria generally does not exhibit any specific external cause and is therefore considered idiopathic. Evidence suggests that up to 30% to 50% of idiopathic cases may be autoimmune and/or related to mast cell/basophil abnormalities. There is further evidence of an autoantibody to the high-affinity receptor for IgE (FcepsilonRI), specifically binding to the alpha-chain (FcepsilonRIalpha), which may be pathogenic. The treatment regimen for urticaria needs to be individualized as the severity and clinical pattern can vary considerably between patients. Histamine antagonists are the mainstays of therapy. For more severe or persistent cases, there are few Food and Drug Administration (FDA)-approved options, and there are limited data from controlled trials. Further research is required to develop safe and more effective agents for this disease.