Which of the following skin lesions typically appear as raised, itchy welts?

Wheals are a type of skin lesion characterized by their raised, swollen appearance and can often be quite itchy. They are typically associated with allergic reactions, insect bites, or irritants. The temporary nature of wheals means they can appear and disappear rapidly, making them distinct from other types of lesions.

Ulcers are deep open sores that usually involve the loss of skin tissue, and while they can be painful, they do not present as raised or itchy welts. Milia are small cysts that form under the skin and usually appear as tiny, white bumps; they are not characterized by redness or itchiness. Pustules are raised lesions that contain pus, often associated with infections or acne, but they do not typically present as the itchy, welty type lesions that wheals do. Thus, wheals are clearly defined by their specific attributes, making them the correct choice for this question.