It wont be inappropriate to call Skin as the third lungs of your body, because Skin also breathes.There are innumerable hair follicles on your skin (small holes) through which it takes in oxygen and sents out carbon dioxide.These hairs lets fresh air enter our body.
It has been proved that when these holes are blocked it would result in death of the person.The poison inside our body,which wont go out through anus or lungs gets expelled through sweat
When dirt gets accumulated over skin,worm infection,eczema,ulcer,fungus etc results.So hair on skin should be kept clean .Also we should give special attention towards clothes we wear.Clothes we wear should be thin,light,and porous ,so that air can come inside.Artificial clothes ( terolin,dacron,nylon ) does not have pores or small holes .Hence air wont enter inside and dirt in body remains inside itself.Thus it results in skin diseases, itching and such diseases.