Itching and skin cancer may be closely connected in some cases. Cutaneous T-cell lymphoma, for example, is a blood cancer that can also attack the skin. When this happens, itching symptoms may persist throughout the body. Squamous cell carcinoma is a skin cancer that may cause itching in large, red patches of the skin. It is important to note that itching is not always present with skin cancer — melanoma and basal cell carcinoma are two types of skin cancer that often do not cause itching.
Cutaneous T-cell lymphoma (CTCL) is a general term that refers to many lymphomas of the skin. It is specifically a cancer involving the T-lymphocytes, or white blood cells, and also impairs the blood and skin. CTCL is a rare disease, and doctors often mistake it for eczema or dermatitis because patients routinely complain of itchy patches of flat, red and scaly skin.
CTCL may occur in plaque or tumor phases as well. A plaque is a thick, raised skin lesion, while a tumor is a larger lesion that may ulcerate. The most common variation of CTCL is mycosis fungoides, and Sezary syndrome is the advanced stage of this disease. Patients with Sezary syndrome typically have reddened skin that is hot, sore, flaking and itchy.
Itching and skin cancer are also connected in many cases of squamous cell carcinoma in situ. This is known as Bowen’s disease, named after the doctor who initially discovered it in the early 1900s. The term "in situ" indicates the skin cancer is in surface form and has not grown inward through the layers of skin. Squamous cell carcinomas may occur anywhere on the body, including mucous membranes and genitals. The most common areas, however, are those frequently exposed to the sun, including legs, arms, hands, lower lip and outer rim of the ear.
Squamous cell carcinoma in situ usually begins as a red, scaly patch. Some spots are brown and resemble melanoma, and the patches often crust or ooze and itch. A biopsy is usually done to confirm diagnosis. People at the greatest risk of developing squamous cell carcinoma are those with blond or red hair, fair skin, and gray, green or blue eyes. Those people with outdoor occupations or who spend excessive leisure time in the sun are in particular danger. Additional risk factors include many severe sunburns early in life, arsenic or chemical exposure and advanced age.
Scaling, itching and skin cancer often appear together. One particular sign is a skin sore that does not heal or abruptly changes in appearance. An existing sore that bleeds, itches or becomes inflamed is another likely symptom of cancer.
Diseases in which itching and skin cancer are typically not linked include melanoma and basal cell carcinoma. Melanoma is usually painless and likely to be marked by a change in the size, color, shape or feel of an existing mole. Basal cell carcinoma is one of the most common skin cancers and may look only slightly different from normal skin. This may be characterized by a skin bump or growth that is waxy, white, light pink or brown.