Hi there ~
I understand your concerns. If your dad are using meth
and has been doing so for a prolonged period of time using IV or inhaled route are very susceptible for skin infection
and connective tissue
as well as organ damage due to infection. I believe that your dad needs to be seen by an infectious disease specialist who along with consultation with a dermatologist
will be able to give your dad the best possible solution. It may involve taking a detailed history, including that of substance use, getting a physical examination, running laboratory tests as well as possibly imaging studies before concluding together on the best course of action. He may ultimately need a psychiatric consultation as he probably would be a good candidate for substance use rehabilitation
as well as to prevent withdrawals from the drug use.
I hope this helps. Take care and have a lovely day!