Suggest Alternative Medication In Place Of Hydroxychloroquine For Sarcoidosis

My son-in-law was prescribed hydroxychloroquine for his sarcoidosis wounds. The wounds are not healing. I understand that this drug stays in the system for a very long time and can induce eye trouble and other side effects. He has very bad skin that never wants to heal and I have come to the conclusion that since he had bad healing of his skin in the first place, that there is something more in his system that is causing this. -- Could he be not absorbing nutrients or needing deficiency testing of needing minerals for this problem.? Any suggestions for the sarcoidosis and the Hydro or any other thoughts on nutrition.