A friend of mine who is paraplegic had the same situation, after trying many remedies, the nurse put honey on her bedsore and it finally healed.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3876612/.
Of course if you have a problem with ants in your area, best to put out ant stakes prior to trying this.
Best of luck to you and your wife.