The diagnosis of nerve compression relies on collecting diagnostic clues from 
the history, physical examination, imaging and diagnostic testing. There are 
several provocative tests to aid in the diagnosis of nerve compression. The 
'Scratch Collapse Test' (SCT) has emerged as a new provocative test to assist in 
the localisation of peripheral nerve compression. This study aims to perform a 
systematic review of literature to assess the data on the reliability of the SCT 
as a diagnostic test for entrapment neuropathy. Ten articles were reviewed. Five 
articles had sufficient numerical data for analysis, and in these five articles, 
the positive predictive values and specificity were high, i.e. between 0.71 and 
0.99 and 0.6 and 0.99, respectively, whereas other values were very variable, 
i.e. individual negative predictive values ranged from 0.15 to 0.92 and the 
sensitivity values ranged from 0.24 to 0.77. Another main finding was the 
versatility of the test in that it can be used for various nerve entrapments and 
to localise the exact level of compression. Literature suggests that SCT has 
potential to be used as a clinical diagnostic tool for entrapment neuropathy. 
However, wide variations in early literature suggest that SCT should not be used 
as a sole diagnostic tool but as an adjunct to a surgeon's diagnostic 
repertoire.