Now, each spinal nerve is in charge of the sensation of a specific area of the skin, called a dermatome.

每一根脊神经都负责着特定区域的感觉，该区域称为皮节。

Herpes zoster or shingles is caused by the reactivation of the virus, with vesicles located along one dermatome.

带状疱疹是由病毒重新激活导致的，皮损沿皮节呈带状排列。

Dermatomes of the spinal nerves of the sacral plexus cover almost the entire surface of the thigh, leg, and foot.

骶神经丛的脊神经的皮节包括几乎整个大腿、小腿和足的表面。

It usually takes 4 weeks for the rash to disappear, but there can be pain in the affected dermatome which lasts for more than 90 days, called postherpetic neuralgia.

皮损一般需要4周消退，但是被感染的皮节区疼痛持续可以超过90天，被叫做带状疱疹后神经痛。

Below the knee, the pain usually follows the dermatome distribution, for example, if the L4 nerve root is compressed, the pain would radiate along side the medial side of the leg.

在膝盖以下，疼痛通常遵循皮节分布：像是如果L4神经根受压，疼痛会沿着小腿的内侧放射。