Dynamic and static components of mechanical hyperalgesia in human hairy skin

作者：Martin Koltzenburg, Lars Lundberg, Erik Torebjörk · 发表于：Pain · 年份：1992 · DOI：10.1016/0304-3959(92)90262-a · 被引用次数：527 · 研究领域：Pain Mechanisms and Treatments、Myofascial pain diagnosis and treatment、Fibromyalgia and Chronic Fatigue Syndrome Research

The principle finding of the present study is that there are two types of mechanical hyperalgesia developing in human hairy skin following injurious stimuli. Mechanical hyperalgesia comprises a dynamic component (brush-evoked pain, allodynia) signalled by large myelinated afferents and a static component (hyperalgesia to pressure stimuli) signalled by unmyelinated afferents. While the static component is only found in the injured area, the dynamic component also extends into a halo of undamaged tissue surrounding the injury. The irritant chemicals, mustard oil or capsaicin, were applied transdermally in 20 subjects to a patch (2 × 2 cm) of hairy skin. Both substances evoked burning pain and hyperalgesia to mechanical stimuli. While stroking normal skin with a cotton bud was perceived only as touch prior to chemical stimulation, there was a distinctly unpleasant sensation afterwards. This component of mechanical hyperalgesia persisted for at least 30 min and was present in the skin exposed to the irritants (primary hyperalgesia) as well as in a zone of untreated skin surrounding the injury (secondary hyperalgesia) measuring 38 ± 4 cm2 after capsaicin. Pressure pain thresholds dropped to 55 ± 8% of baseline level after mustard oil and to 46 ± 9% after capsaicin. However, this drop of thresholds was short-lived, lasting 5 min following mustard oil but persisting more than 30 min following capsaicin treatment. The reduction of pressure pain thresholds was only observed for treate...