The exact diagnosis is not possible by the symptomatology given by you.
Still your skin problem can be somewhat relieved if you apply emollients 3-4 times daily.
Avoid sun exposure and frequent washing of hands. Avoid harsh soaps and detergents. Avoid exposure to dust. Avoid maize, if it is a constituent of your diet.
Consult a general physician for constipation
for skin problems.
Mind having regular follow ups because skin problems at times demand long and regular follow up.