Itchy skin, medically known as pruritus, is a sensation of irritation and discomfort that makes you want to scratch. Itching can be a symptom of certain types of cancer. Itching can also be a reaction to certain cancer treatments.

A of over 16,000 people in the Johns Hopkins Health System indicated that patients with generalized itching were more likely to have cancer than patients who didn’t notice itch. The types of cancers that were most commonly associated with itching included:

Skin cancer

Typically, skin cancer is identified by a new or changing spot on the skin. In some cases, itchiness might be the reason that the spot was noticed.

Pancreatic cancer

Those with pancreatic cancer may experience itching. The itch, however, isn’t a direct symptom of the cancer. Jaundice may develop as the result of a tumor blocking the bile duct and chemicals in the bile can enter the skin and cause itching.

Lymphoma

Itching is a common symptom of skin lymphoma, T-cell lymphoma, and Hodgkin’s lymphoma. Itching is less common in most types of non-Hodgkin’s lymphoma. The itching might be caused by chemicals released by the immune system in reaction to the lymphoma cells.

Polycythemia vera

In polycythemia vera, one of the slow-growing blood cancers in a group known as myeloproliferative neoplasms, itchiness may be a symptom. The itching might be especially noticeable after a hot shower or bath.

Itching as a result of cancer treatment may be an allergic reaction. There are also cancer treatments associated with long-term itching, including:

Itching might also be caused by hormone therapy for breast cancer, such as:

  • anastrozole (Arimidex)
  • exemestane (Aromasin)
  • fulvestrant (Faslodex)
  • letrozole (Femara)
  • raloxifene (Evista)
  • toremifene (Fareston)
  • tamoxifen (Soltamox)

Just because your skin itches doesn’t mean that you have cancer. It’s likely that your pruritus is caused by something more common such as:

There are also underlying conditions that can cause itching, including:

If you think itching may be a sign of cancer, contact your doctor so they can check on a diagnosis. Contact your primary doctor or oncologist if:

  • your itching lasts for more than two days
  • your urine is dark like the color of tea
  • your skin turns yellowish
  • you scratch your skin until it’s open or bleeding
  • you have a rash that worsens with the application of ointments or creams
  • your skin is bright red or has blisters or crusts
  • you have pus or drainage coming from the skin with an unpleasant odor
  • you’re unable to sleep through the night because of itching
  • you have signs of a severe allergic reaction such as shortness of breath, hives or swelling of the face or throat

There are many potential causes of itching. In some cases, it may be a symptom of certain types of cancer or cancer treatment.

If you have cancer and experience unusual itching, see your doctor to make sure it’s not an indication of a serious problem. Your doctor can help you determine the specific cause and give you some suggestions about easing the itch.

If you don’t have a cancer diagnosis and are experiencing unusual, persistent itching, your doctor should be able to pinpoint the cause and recommend ways to relieve it.