What is a common feature of a wheal?

A wheal is characterized by being raised and often results from an allergic reaction or irritant. One of the defining features of a wheal is that it is typically inflamed, causing discomfort and itching at the site. This inflammation occurs due to an accumulation of fluid in the tissues, which triggers the body's immune response and leads to the itchy sensation associated with wheals. This is commonly observed in conditions such as hives (urticaria), where multiple wheals can appear on the skin.

In contrast, the other options describe characteristics that do not align with the typical presentation of a wheal. For instance, wheals are not generally necrotic or scaly; instead, they are smooth and raised. These features help differentiate wheals from other skin lesions, confirming that inflamed and itchy is the most accurate description.