hyperæstesi

Hyperæstesi, also spelled hyperesthesia, is a clinical finding characterized by an abnormal increase in sensitivity to sensory stimuli. It refers to heightened responses to tactile, thermal, or other sensory input, and can be localized to a body region or occur more diffusely. The term combines Greek roots meaning over sensation.

Tactile hyperesthesia denotes increased sensitivity to touch, while thermal hyperesthesia refers to heightened responses to temperature. Allodynia is a related phenomenon where non-noxious stimuli provoke pain, and hyperalgesia denotes an exaggerated pain response to normally painful stimuli. These distinctions help describe the sensory abnormalities observed in various conditions.

The mechanisms underlying hyperæstesi involve both peripheral and central nervous system processes. Peripheral sensitization of nociceptors lowers the threshold for activation, while central sensitization in the spinal cord and brain enhances pain signaling and sensory processing. Altered inhibitory control and cortical reorganization may also contribute, particularly in chronic pain syndromes.

Hyperæstesi occurs in a wide range of disorders. Common causes include peripheral neuropathies (e.g., diabetic neuropathy), postherpetic neuralgia, nerve compression or trauma, inflammatory or autoimmune diseases, infections, stroke, spinal cord injury, and complex regional pain syndrome. It can be a feature of central nervous system disorders or result from medication effects.

Diagnosis is clinical, supported by quantitative sensory testing or nerve conduction studies when indicated. Evaluation aims to differentiate hyperesthesia from hypoesthesia or paresthesias and to identify an underlying condition.

Management focuses on treating the underlying cause and mitigating symptoms. Options include pharmacologic therapies such as anticonvulsants and antidepressants for neuropathic pain, topical agents, physical therapy, desensitization techniques, and psychological support. Prognosis varies with etiology and response to treatment. See also allodynia, hyperalgesia, and neuropathic pain.