Hello,
Peeling and flaking hands can be due to contact dermatitis and contact with harsh detergents, soaps and lotions. Sometimes cold, dry air can cause peeling and dermatitis or fungal infections can also cause peeling.
Wash the areas several times with fresh water. Do not use any cosmetic products at the sites. You can apply some calamine lotion at the rash as it will help in soothing the skin. For mild-moderate symptoms a weak steroid may be used, whilst more severe cases require a higher-potency steroid.
Symptoms can be exacerbated by dryness of the skin. Use good quality moisturizers to prevent moisture loss from the skin. During the day, hydrate and protect hands with a protective and moisturizing cream.
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 dermatologist. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.
it sounds like callus buildup. when i first started playing guitar my fingers would get extra skin that peeled, and after being around other musicians, i was told the fingers build calluses because of the strings, which explained why when i first started playing, my fingers were really sore, but once i got calluses, the strings didnt hurt my fingers anymore. i did end up with really thick calluses on my fingertips, but i loved playing guitar, so i didnt mind. if he does any kind of hobby where he uses his fingers, this could easily be the cause.