Ultrasonography is convenient and useful for assessment and follow-up of Takayasu's arteritis.

A 20-year-old woman first came to our hospital complaining of high fever and pain affecting the whole body. Takayasu's arteritis (TA) was diagnosed. Following full-body examination, many vessels between the bilateral neck and iliac arteries were found to be impaired. Ultrasonography (US) showed the characteristic wall thickening of TA in the left common carotid artery. After starting prednisolone treatment (40 mg/day), symptoms improved quickly and vessel walls gradually became thinner. However, chest pain recurred when prednisolone was tapered to 20 mg/day. Blood tests showed no signs of recurring inflammation, and US revealed worsened wall thickening only in the left carotid artery. We therefore diagnosed local recurrence of activation of TA. Assessing local recurrence of TA with a blood test is difficult, particularly after prescribing steroids. In this case, US identified the local changes attributable to TA before any other diagnostic modality. US can be useful in assessing inflammation and offers a good strategic tool for initial diagnosis of TA.