pyoderma gangrenosum
noun [ U ] medical specialized uk/paɪ.əˌdɜː.mə ɡæŋ.ɡrɪˈnəʊs.əm/ us/ˌpaɪ.əˈdɝː.mə ˌɡæŋ.ɡrɪˈnoʊ.səm/
坏疽性脓皮病
a skin condition in which large ulcers containing pus (= a thick yellow liquid) form and produce serious wounds