  ▁failure , ▁o ed ema , ▁imp a ired ▁ability ▁to ▁look ▁after ▁personal ▁care ▁( e . g . ▁visual ▁imp air ment ) ▁are ▁further ▁risk ▁factors ▁for ▁di ab etic ▁foot ▁ul cer . ▁ ▁People ▁with ▁di ab etes ▁often ▁develop ▁di ab etic ▁ne urop ath y ▁due ▁to ▁several ▁met abol ic ▁and ▁ne uro vas cular ▁factors . ▁Per i pher al ▁ne urop ath y ▁causes ▁loss ▁of ▁pain ▁or ▁feeling ▁in ▁the ▁to es , ▁feet , ▁legs ▁and ▁arms ▁due ▁to ▁dist al ▁n erve ▁damage ▁and ▁low ▁blood ▁flow . ▁Bl ister s ▁and ▁s ores ▁appear ▁on ▁num b ▁areas ▁of ▁the ▁feet ▁and ▁legs ▁such ▁as ▁met atar so - phal ange al ▁joint s , ▁he el ▁region ▁and ▁as ▁a ▁result ▁pressure ▁or ▁injury ▁goes ▁un not iced ▁and ▁eventually ▁become ▁portal ▁of ▁entry ▁for ▁b acter ia ▁and ▁in fection . ▁ ▁Path oph ys i ology ▁ ▁Ext rac ell ular ▁matrix ▁ ▁Ext ra ▁cell ular ▁matrix ▁( or ▁" EC M ") ▁is ▁the ▁external ▁struct ural ▁framework ▁that ▁cells ▁attach ▁to ▁in ▁mult ic ell ular ▁organ isms . ▁The ▁der mis ▁lies ▁below ▁the ▁e pid erm is , ▁and ▁these ▁two ▁layers ▁are ▁collect ively ▁known ▁as ▁the ▁skin . ▁D erm al ▁skin ▁is ▁primarily ▁a ▁combination ▁of ▁fib ro bl asts ▁growing ▁in ▁this ▁matrix . ▁The ▁specific ▁species ▁of ▁EC M ▁of ▁connect ive ▁t issues ▁often