It may work by soothing the skin
Other possibility is of
erythroderma.It is a generalized skin
disorder characterized by reddening and scaling of
the skin and produced by several skin diseases, such as psoriasis, contact dermatitis, drug reactions, and mycosis fungoides (a cutaneous lymphoma).
I feel that an examination by a dermatologist will be the best.Other conditions like liver and kidney disorders,diabetes, iron deficiency
anemia and thyroid disorders also have to be ruled out.