Suggest Remedy For Excessive Skin Dryness And Itching

My father (aged about 65 years) has developed a skin problem recently. His skin has become dry causing excessive itching. The problem started on his back and later spread to other body parts. One can see certain rashes on the skin as well. Doctor advised using a shower gel and alocin after bath. This helped for few days, but despite continous usage of the shower gel and alocin, the problem has resurfaced. Please advice. Thanks. RG