Also, consider a possible fungal involvement on the skin. Topically, you can use tea tree essential oil diluted in expeller pressed coconut oil. Both are anti-bacterial and anti-fungal. The link Mrs D provided has a product with neem oil which is anti-fungal also but I couldn't find what all the ingredients are in the product. Unless they disclose everything in the product, I'm reluctant to buy it.

You can also soak your feet in epsom salt to soften the skin before applying any lotion.

Attack it from two fronts....internally and topically.