What defines allodynia?

Allodynia is specifically characterized by a painful response to stimuli that are typically not considered harmful or painful. This condition occurs when the nervous system becomes sensitized, and normal sensations—such as light touch, temperature change, or pressure—are perceived as painful. This can significantly impact a person's quality of life, as activities that were once comfortable become sources of discomfort or pain.

The other options highlight different pain phenomena. Pain perceived from a different location refers to referred pain, where pain is felt in a part of the body other than its actual source. An exaggerated response to pain suggests hyperalgesia, where a person has an increased sensitivity to pain, but this is distinct from allodynia, which specifically involves non-painful stimuli. Pain that radiates from one area to another points to a pattern of referred pain as well, rather than the mechanisms of allodynia. Therefore, option B accurately captures the essence of allodynia and its unique characteristics.