Yes Loosie,
a birth defect such as blindness caused by genes cannot be rectified thru fasting or Natural Hygiene either, but in a skin condition that may not be caused by a genetic defect, it is very worthwhile trying everything that Nature has to offer, including a complete fast, or several complete fasts, with optimum nutrition, and a natural physiological lifestyle thereafter to eliminate that possibility.
I was not trying to imply that there are not genetic diseases at all, but it is more than worthwhile to try everything possible to cure the condition, before conceding that the possibility that nothing can be done at all.