The liver scratch test is a maneuver traditionally used to locate the lower edge of the liver using a finger to scratch the abdominal surface and a stethoscope to listen to its transmission pattern.
Performing the Test
Have the patient lie supine.
Place the diaphragm of the stethoscope over the approximate location of the liver.
Start scratching the skin lightly with your fingernail, below the suspected border of the liver and move superiorly.
If the transmission of the scratching sound improves and the grating gets louder, you may be auscultating over the liver.
Interpretation
Although evidence is somewhat conflicting, the few studies that have been conducted suggest that the test is unreliable and less accurate than palpation.
References
McGee S. Evidence Based Physical Diagnosis, Second Edition. St. Louis, MO: Saunders Elsevier; 2007.