What Causes Facial, Arms And Legs Skin Discoloration With Walking Problems?

I have a 7 year old daughter who has been experiencing skin disclorations such pink blots on her face, arms and legs tta have progressively gotten worse over the past year she also begun experencing problems walking around the same time the skin disclorations began to appear, I have been told by a doctor that has has the mobility of a 70 year old peson the doctor have ran test but can't seem to figure ot what's wrong any insight?