1. A. Wheals are rounded or flat-topped papules or plaques that are characteristically evanescent, disappearing within hours. An eruption consisting of wheals is termed urticaria and usually itches. B. Wheals may be tiny papules 3 to 4 mm in diameter, as in cholinergic urticaria. C. Alternatively, wheals may present as large, coalescing plaques, as in allergic reactions to penicillin or other drugs or alimentary allergens. (Reprinted with permission from Stewart MI, Bernhard JD, Cropley TG, Fitzpatrick TB. The structure of skin lesions and fundamentals of diagnosis. In: Freedberg IM, Eisen AZ, Wolff K, et al., eds. Fitzpatrick’s Dermatology in General Medicine, 6th ed. New York: McGraw-Hill, 2003:18.)
Source: Dermatologic Drug Reactions and Common Skin Conditions, Pharmacotherapy: A Pathophysiologic Approach, 10e
Citation: DiPiro JT, Talbert RL, Yee GC, Matzke GR, Wells BG, Posey L. Pharmacotherapy: A Pathophysiologic Approach, 10e; 2017 Available at: Accessed: December 26, 2017
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