Thanks for writing to us.
The dryness over knuckles could have possible occured due to frictional injury
or due to contact dermatitis
to some irritant or allergen.
Treatment requires use of an intensive moisturising cream containing urea and lactic acid multiple times in a day. Use a potent steroid
antibiotic cream to help the area heal. Wear gloves while working. Avoid contact with harsh soaps and chemicals.
Hope that helped.