Stretch and pinch tests to assess the suitable management for acne rolling scars

Demonstration of stretch and pinch tests with corresponding ultrasound examination

The acne rolling scar on the right medial zygoma showing a dimple sign in a pinch test and an uneven sign in a stretch test. The ultrasound examination of the acne rolling scar at rest showed a homogenous band (red box) disrupting and blurring the clear dermoepidermal junction and the junction between the dermis and the subcutaneous fascia. The irregularity of the skin surface was more evident after pinching and the homogenous blurring persisted after stretching, corresponding to a dimple sign and an uneven sign, respectively.
Red line, dermoepidermal junction; Yellow line, junction between the dermis and the subcutaneous fascia