Application of high frequency ultrasound in dermatology.

High frequency ultrasound (HFUS) refers to the ultrasound probe frequency of more than 10 MHz. HFUS has shorter wavelengths, is absorbed more easily, and is therefore not as penetrating. This explains its use for superficial structures and hence its increasing application in the field of dermatology. HFUS is a simple, reliable, and noninvasive technique that is being used along with the physical examination for the assessment, diagnosis, and management of many dermatologic conditions. In addition, it can also be used for the evaluation of normal skin structure. In the present article, we aim to describe the basic principles of cutaneous ultrasound, imaging findings of normal skin, and current applications of HFUS in the diagnosis, treatment, and follow-up of various dermatologic conditions.