Snapshot A45-year-old woman with a history of systemic lupus erythematous presents to her dermatologist’s office with hives. She complains that this is the “worst it’s ever been.” She has been having episodes of itchy rashes on and off for about 6 months now. On physical exam, her entire back is covered with raised, red wheals. Some are annular. The lesions are blanching and intensely pruritic. She denies any difficulty breathing or any GI symptoms. She has a history of childhood asthma and hypothyroidism, currently on levothyroxine. The lesions usually resolve spontaneously, but this episode is particularly pruritic. She is given an anti-histamine. Introduction Pruritic inflammation of the skin commonly known as “hives” Characterized by superficial, localized edema and erythema Timeline login to view 2 more bullets Triggers of acute urticaria login to view 11 more bullets Chronic urticarial is usually idiopathic login to view 1 more bullet Epidemiology Most frequent dermatologic disorder seen in the emergency room Etiology Pathogenesis login to view 5 more bullets Identified in 40-60% of acute cases and 10-20% in chronic cases Many different types of urticarial with wide range of severity login to view 4 more bullets Presentation Symptoms login to view 4 more bullets Physical exam login to view 15 more bullets Evaluation Labs or biopsy not indicated for acute urticaria unless diagnosis is unclear ↑ IgE For chronic or recurrent urticarial login to view 1 more bullet Biopsy of lesion login to view 2 more bullets Differential Diagnosis Hereditary angioedema Contact dermatitis Multiple insect bites Erythema multiforme Treatment If known, discontinue offending agent If concern for airway compromise login to view 1 more bullet Anti-histamines login to view 2 more bullets For urticarial vasculitis login to view 4 more bullets Prevention, and Complications Prevention login to view 2 more bullets Complications login to view 4 more bullets Prognosis Most resolve spontaneously