dermatologic disorders
Urticaria
Introduction
Urticaria consists of migratory, well-circumscribed, erythematous, pruritic plaques on the skin. Urticaria also may be accompanied by Angioedema , which results from mast cell and basophil activation in the deeper dermis and subcutaneous tissues and manifests as edema of the face and lips, extremities, or genitals. Angioedema can occur in the bowel and manifest as colicky abdominal pain. Angioedema can be life-threatening if airway obstruction occurs because of laryngeal edema or tongue swelling. (See also Evaluation of the Dermatologic Patient .) 