Urticaria (Hives; Wheals) By Julia Benedetti, MD, Harvard Medical School Reviewed / Revised Dec 2021 | Modified Sep 2022 View Patient Education Pathophysiology Etiology Evaluation Treatment Geriatrics Essentials Key Points Topic Resources Urticaria Cold-Induced Urticaria Urticaria Pigmentosa (Thorax) Urticaria Pigmentosa (Leg) Urticaria Pigmentosa (Child) Urticaria Pigmentosa (Infant) Solar Urticaria Urticaria and Bullous Pemphigoid Dermatographism Some Causes of Urticaria Urticaria consists of migratory, well-circumscribed, erythematous, pruritic plaques on the skin.