What Causes Discoid Lupus Erythematosus And How To Treat It?

Hello Doctor, My mom consulted a skin specialist for skin problem the doctor said it was a case of DLE n suggested few tests along with medicines such as CBP,ESR,LE CELLS,SERUM CREATININE ,BLOOD UREA, CUE,FBS,PLBS,CHEST PA VIEW,all the reports were normal except for the chest pa view with radiologist comment as CALCIFIL DENSITY RIGHT LOWER ZONE,TRACHEA CENTRAL CALCIFIC DENSITY,could u suggest the cause of this n is there a serious problem,n what steps or further medications to be taken.The doc adviced for two test suspecting TB,one is the swab test n the other is skin test r these necessary