TY - CHAP M1 - Book, Section TI - Section 13. Urticarial, Purpuric, and Vascular Reactions A1 - Weinberg, Samuel A1 - Prose, Neil S. A1 - Kristal, Leonard PY - 2008 T2 - Color Atlas of Pediatric Dermatology, 4e AB - A wheal is an edematous papule that may enlarge to form a pink, sharply circumscribed, elevated plaque. The typical lesions of urticaria, pictured here, have a suggestion of central clearing. By definition, the individual lesions of urticaria evolve quickly and resolve within 24–48 hours. They are usually accompanied by severe pruritus. The most common etiologies of urticaria are medications, foods, and viral (Fig. 13-2) and bacterial infections. Autoimmune disease and malignancy are extremely rare causes. In the child with chronic urticaria, it is often difficult or impossible to identify a single cause. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/04/18 UR - accesspediatrics.mhmedical.com/content.aspx?aid=6988156 ER -