Hi welcome to health care magic forum. According to to your description your condition may be due to either vit. Adefeciency or auto imune xerosis . As it is already existing since 20 years, we can decide it is not curable, what we can expect is to maintain comfertable recovery from the secondary infections as appeared now.
When ever you have pus, you consider it to be secondary infection and consult a dermatologist
. Antibiotics and supporting drugs will defenitely clear the present situation .
Besides i advise youto follow some diet recommendations as take more of green leafy vegetables, pulses, sprouts, milk, egg, meat, etc to provide proteins
, iron, and vitamin A
and other vitamins
to maintain the skin and body healthy, Wishing for a quick and comfertable life and thanks for calling.