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ATRA seemed to be the most possible etiology of erythema nodosum in our patients .
 Chemical: ATRA; Disease: erythema nodosum
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: ATRA; Disease: erythema nodosum