One of the most common signs of melanoma is an oddly shaped mole that forms on the skin and looks different from other moles on a person's body, according to the American Academy of Dermatology. A persistent skin rash could be a symptom of another type of cancer, called cutaneous T-cell lymphoma, notes the Lymphoma Research Foundation. Other signs of cutaneous T-cell lymphoma include dry skin, itching and enlarged lymph nodes in conjunction with a red rash.
Patients who suspect melanoma should examine moles on the skin for various signs, explains the American Academy of Dermatology. One half of the mole may look different than the other half, or the mole may have an irregular shape. The mole could also vary in color, such as going from brown to red, white, black or blue. The diameter of a melanoma could reach wider than that of a pencil eraser, and the mole may grow larger as it evolves.
People with cutaneous T-cell lymphoma have a blood cancer that reveals itself close to the skin, according to the Lymphoma Research Foundation. One type of this cancer, known as mycosis fungoides, has three types of skin symptoms. One symptom may look like flat patches of redness similar to a rash. Plaques associated with mycosis fungoides could look like eczema, psoriasis or dermatitis due to the raised, itchy lesions on the skin. Tumors on the surface may appear similar to raised bumps that may eventually form an open sore.