Hello,
For the note, you have to consult a dermatologist and get it examined. The dermatologist will give you a prescription describing the condition and the treatment will be prescribed. You can talk to your authorities regarding the note if it is acceptable to them.
. Place protective covering or bandages over the sore to decrease friction on the skin until the sore heals. Rub sandpaper disks or pumice stone over hard thickened regions. Soak feet or hands
. Then rub with a pumice stone and apply some moisturizer.
If still the calluses persist, then please go in for removal by surgical means or with keratolytic agents (medicines that break up hardened areas of skin). Shaving or cutting off the hardened area on the skin by a doctor is also helpful.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.