1646
A 33-year - old male presented with brown discolouration of the fingernails following the application of 4 % hydroquinone in sorbolene cream and 0.1 % tretinoin cream to the face intermittently for 9 months .
 brown discolouration of the fingernails, 0.1 % tretinoin cream; brown discolouration of the fingernails, 4 % hydroquinone in sorbolene cream
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: adverse effect 
Text: {0} 
Answer:
 brown discolouration of the fingernails, 0.1 % tretinoin cream; brown discolouration of the fingernails, 4 % hydroquinone in sorbolene cream