A round, raised skin lesion with itching that indicates a positive reaction to allergic testing is called what?

A round, raised skin lesion that is associated with itching and indicates a positive reaction to allergic testing is known as a wheal. Wheals are typically characterized by their elevated, swollen appearance and often occur as part of an allergic response, commonly seen in conditions like urticaria (hives). When the skin is exposed to an allergen, the immune response can lead to localized edema (swelling) in the dermis, creating the characteristic wheal.

In contrast, a macule refers to a flat, discolored area of skin that does not involve elevation, while a papule is a small, solid, raised bump that may or may not be itchy but does not necessarily indicate an allergic reaction. A vesicle is a fluid-filled blister, which is also not the correct description for the lesion associated with allergic reactions. Therefore, the defining features of a wheal align perfectly with the symptoms and characteristics described in the question.