A rash can indicate kidney failure and kidney cancer, according to Healthline and the American Academy of Dermatology. When kidney disease has progressed to an advanced stage, waste products building up in the blood cause the skin to react, and rashes or severe itching are the results.
An inflammatory muscle disease called dermatomyositis produces significant changes in the skin that are linked to numerous internal cancers, including kidney cancer, explains the American Academy of Dermatology. Signs on the skin include scaly, raised bumps on the knuckles and a purple-colored rash on the upper eyelids and on sunlight-exposed areas of skin. In one case, a patient who received a dermatomyositis diagnosis was later diagnosed with an early stage, treatable kidney cancer.