Thanks for writing to us.
There could be many causes for hyperpigmentation of feet and fingers like acanthosis nigricans
, eczema, vitamin B12 deficiency
, Addison's disease etc. Parathyroidectomy may lead to hypoparathyroidism
which sometimes not commonly may cause exfoliatiave dermatitis ie dry red scaly skin.
It would be imperative that you visit a dermatologist
near by to ascertain the diagnosis and start an appropriate treatment.