What is the characteristic symptom of allodynia?

Allodynia is characterized by experiencing pain from normally non-painful stimuli. This means that sensations that should not typically cause pain, such as light touch or pressure, can provoke significant discomfort or pain in individuals with this condition. This symptom can manifest in various ways, such as experiencing pain when wearing clothes, touching the skin, or even during activities that are usually painless.

In contrast, uncontrollable itching is associated with other conditions like allergic reactions or skin disorders, while a severe burning sensation may be indicative of neuropathic pain or other specific pain disorders. Localized redness often corresponds to inflammation or irritation of the skin, which does not align with the defining symptom of allodynia. Therefore, the hallmark symptom of this condition is indeed the perception of pain in response to innocuous stimuli, making the correct answer the sensation of pain from touch.