痛痒是比喻疾苦或紧要的事。不关痛痒用来比喻切身相关的事。指与自身利害没有关系。

出自《朱子语类》卷一０一：“那不关痛痒底是不仁。”

那么不关痛痒用英语怎么说？

不关痛痒可以用have no compassion for others，a matter of no consequence，be perfunctory，do not care a bit，irrelevant，immaterial，insignificant，pointless，show no concern，without any bite等，例如：

1.(神色肃穆) 我接受你的观点，查尔斯，但这些人根本不关痛痒，所以我根本不会担心。
VC: [In sombre mood] I take your point, Charles, but these people really are an irrelevance, so I wouldn't worry about it. 

2.近30年来，泰勒指出，美国经历了几次经济衰退时期，站在历史的角度来看，稍纵即逝且不关痛痒。
For nearly 30 years, Taylor points out, the few downturns the U.S. has suffered have, in historical terms, been both short and shallow. 

3.这种似乎不关痛痒的袭击的效果比乍看上去大得多，影响很广泛。
The results of this seemingly innocuous raid were more widespread than appears at first glance.