please, need advice!!

Hi everyone,
this is the first time i have posted on this forum.
I am i a missionary kid from Mozambique, originally from South Africa. We work with children here. anyway, the one homeless boy who is staying with us seems to have a deficiency in his body, i was hoping you guys could help me figure out what. you see, whenever he has a minor scratch, it seems to be healing fine, but then it starts festering and bursts open. and he has a cut on his one toe he got from playing, and its about two weeks ago and it won't heal either. i am putting on antibiotic cream, do you think i should give him antibiotic pills too? it keeps festering, and there is this gooey oily stuff coming out at times. the government hospital where we live i know won't be able to help me with something like this, they consider it too "minor" for their attention.
i would appreciate absolutely any advice!
thank you in advance!!
isaac