formication

/ˌfɔːrmɪˈkeɪʃən/
noun
  1. A sensation that feels like insects are crawling on or under the skin, often caused by a medical condition or drug use.
    • The patient complained of formication in her arms, which the doctor said might be a side effect of the medication.
    • Some people with anxiety report formication, feeling as if bugs are crawling on their skin.
    • After the spider bite, he experienced formication and kept scratching his leg.