What cancer can cause itchy skin?
Itchy skin, also known as pruritus in medical terms, is a feeling of irritation and discomfort that causes people to scratch. Itching can be a sign of cancer in some cases. Itching is also a side effect of some cancer treatments. Individuals with generalised itching were more likely to have cancer than patients who did not feel the itch, according to a 2018 research of 16,000 participants at the John Hopkins Health System. The following cancers were found to be most frequently related with itching:
Blood cancer, such as leukemia and lymphoma
Bile duct cancer
Gallbladder cancer
Liver cancer
Skin cancer
Skin Cancer
A new or changing area on the skin is usually the first sign of skin cancer. Itching may have been the reason for the area to be detected in some circumstances. The most frequent type of cancer that causes itching is skin cancer. With basal cell carcinoma and squamous cell carcinoma, itching is more common than with melanoma.
Vulvar cancer and Anal cancer
Itching in the vulvar and vaginal regions, as well as the anal region, is more likely owing to another cause, however cancers in these areas still cause itching.
Breast cancer
Itching as a breast cancer symptom is uncommon, although it can happen. Inflammatory breast cancer, unlike other types of breast cancer, often begins as a rash or a breast infection (mastitis). Before symptoms intensify, itching and a tiny rash may appear, which might be mistaken for an insect bite. Itching is a common symptom of Paget’s disease of the breast, which is commonly accompanied with a dry, scaly rash on the nipple.
Pancreatic cancer
Itching is a common symptom of pancreatic cancer. The itch, on the other hand, is not a direct sign of malignancy. A tumour blocking the bile duct can cause jaundice, and chemicals in the bile can seep into the skin and cause itching.
Any cancer that obstructs the bile ducts might result in blockage and a build-up of bile salts in the skin. This is particularly common with pancreatic cancer. Other signs and symptoms include jaundice, abdominal pain, ascites (abdominal fluid build-up), and abdominal pain.
Lymphoma
Skin lymphoma, T-cell lymphoma, and Hodgkin’s lymphoma include itching as a symptom. In most kinds of non-lymphoma, Hodgkin’s itching is less common. Itching could be induced by immune system chemicals secreted in response to lymphoma cells.
Itching can occur in cutaneous T cell lymphomas due to both direct skin involvement and the release of inflammatory chemicals such as interleukin-31. Itching is a common symptom of myelodysplastic diseases such as polycythemia vera.
Polycythemia vera
Itching can be a sign of polycythemia vera, one of the slow-growing blood cancers known as myeloproliferative neoplasms. Itching may be more obvious after taking a hot shower or bath.
Metastatic cancer
Itching may be a symptom of metastatic cancer. Breast cancer is the most prevalent cause of skin metastases in women, while lung cancer is the most common cause in men. Other tumours, such as colon cancer, can spread to the skin. Itching may occur as a result of liver metastases. Lung cancer, breast cancer, colon cancer, and melanoma are the most prevalent cancers to spread to the liver.
Cancer treatments that cause itching
Itching as a side effect of cancer treatment could indicate an allergic reaction. Long-term itching can also be associated with cancer treatments such as:
Chemotherapy
Radiation therapy
Bortezomb (Velcade)
Brentuximab vedotin (Adcetris)
Ibrutinib (Imbruvica)
Interferons
Interleukin-2
Rituximab (Rituxan, MabThera)
Itching may also be caused by breast cancer hormone therapy, such as:
Anastrozole (Arimidex)
Exemestane (Aromasin)
Fulvestrant (Falsodex)
Letrozole (Femara)
Raloxifene (Evista)
Toremifene (Fareston)
Tamoxifen (Soltamox)
Itching can be caused by direct skin irritation (such as with skin cancer or skin metastases), the accumulation of bile salts, or substances secreted by a tumour or the body in response to a tumour. Though it can be difficult to tell the difference between itching caused by cancer and itching caused by benign causes, there are a few signs to look for.
Prevalence
It is unclear how frequently itching occurs as a symptom or early symptom of cancer, but it is assumed that 10% to 25% of patients who develop generalised itching without a rash have an underlying systemic (body-wide) disease. In one study of nearly 17,000 participants, those who experienced generalised itching were 5.76 times more likely than those who did not have itching to have an underlying cancer. Liver cancer, gallbladder cancer, bile duct cancer, blood-related cancers like lymphomas and leukemias, and skin cancer were the most commonly linked cancers.
Significant itching was found in 30% of individuals with Hodgkin lymphoma, 15% of those with non-Hodgkin lymphoma, 5% of those with leukemia, and over 50% of those with myeloproliferative diseases who had recently been diagnosed with cancer.
Is cancer causing the itching?
Itching caused by cancer can be similar to itching caused by skin diseases or other benign causes, but there are key differences to be aware of. Itching caused by cancer may have the following characteristics:
Itching as a result of exposure to water (aquagenic pruritus)
Hives or a rash are not present (though sometimes a rash occurs due to repeated scratching)
Other signs and symptoms of lymphoma, such as jaundice (a yellowish colouring of the skin) and lymphoma B symptoms (fever, weight loss, and drenching night sweats).
Furthermore, cancer-related itching is most severe in the lower legs and chest, and it might be accompanied by a burning sensation.
How cancer causes itching
Itching can be caused by a variety of factors, including cancer. Itching is caused by nerve endings in the body (similar to pain receptors). Itching can be caused by anything that irritates these nerve endings.
Direct inflammation
Itching is most commonly caused by cancers that affect the skin or mucous membranes in some way. This could include skin cancers, breast cancers including inflammatory breast cancer, Paget’s disease of the nipple, and, of course, any cancer that spreads (metastasizes) to the skin. The itch linked with vulvar and anal cancers may also be caused by direct inflammation.
Build-up of Bile Salts
The build-up of bile salts in the skin might be caused by a blockage of the bile ducts or the disintegration of red blood cells. This frequently results in intense itching. This can happen with leukemias and lymphomas (cell disintegration), abdominal cancers such as liver and gallbladder cancers, and any disease that spreads to the liver (such as breast, lung, colon, and more). The accumulation of bile salts is sometimes, but not always, linked to jaundice (a yellowish appearance of the skin).
Secretion of chemicals
Chemicals secreted by tumours (which produce neoplastic symptoms) or compounds produced by the body reacting to a tumour, can cause itching. The itching is usually worse in the legs. In some circumstances, paraneoplastic symptoms like itching can occur weeks or months before cancers like non-small cell lung cancer or lymphomas are diagnosed.
Cytokines (inflammatory chemicals generated from immune cells in reaction to lymphomas), substance P, neuropeptides, prostaglandins, and other chemicals have been linked to this effect. Some of these chemicals produce itching by acting directly on nerve endings, while others may trigger the production of histamine by mast cells and other methods. Itching may occur alone or in association with rashes such as erythroderma, acanthosis nigricans, dermatomyositis, Grover’s disease, or eruptive seborreheic keratosis.
Hormonal changes
Itching can be caused by hormonal changes due to cancer or cancer treatments in a number of ways. Dryness can be caused by menopause in women, whether it is natural, surgical, or medically induced, such as in the case of breast cancer. Hormonal changes may also lead to hot flashes. Itching is a common side effect of hot flashes, which are often accompanied by sweats.
Managing itching is critical for cancer patients’ quality of life, especially when itching is severe, as it is with liver metastases or T cell lymphomas. Itching is often relieved by treating the underlying cancer. However, in other cases, such as with advanced cancers, this is not always feasible. It may take some time for the itching to go away.
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