hi i think u are suffering from chronic superficial folliculitis
of legs or lichen planus
.as the lesions are spreading to stomach chronic superficial folliculitis can be ruled out.lichen planus is a papulosquamous disorder
which is immunological orgin presents as erythematous papules all over the body which are itchy and develop as purlish scars all over the body.
It can be cured by antihistamine,antibiotic and application of moisteriser along with dipsalic ointment can cure it.even if it is pleva the same treatment works