My dad is diabetic and his left feet from his big toe has water blisters how do i treat it? we drained it but it came back please help

Tincture of time: Hi. Assuming it's not infected (they usually are not), conservative management (watch and wait) will resolve the issue. Many patients aren't that patient, however, so I will in some cases remove the top of the blister, which speeds recovery, although that is not a standard recommendation in the foot field. Watch it & make sure there are no signs of infection. I hope his diabetes is well controlled