A person’s armpits may itch due to irritation, infection, or a skin condition, such as eczema or dermatitis. Rarely, however, itchy armpits may be a sign of cancer, such as lymphoma or inflammatory breast cancer.

This article describes two types of cancer that may cause itchy armpits. We also outline six less severe causes of underarm itching, tips on preventing itching, and when to see a doctor.

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The armpit, also known as the axilla, refers to the underside of the shoulder joint, where the shoulder connects to the arm. This area features many different structures, such as skin, hair, sweat glands, nerve endings, blood vessels, and lymph nodes.

Due to all these structures, in addition to the warmth and dampness of the armpit, it is not uncommon for a person to experience itchy armpits. As it is a sensitive area, people are likely to notice any irritation. Usually, itching can result from inflammation, rashes, infections, or allergies. However, itching may occur on rare occasions due to a more serious issue, such as cancer.

Learn more about itchy skin.

Most cases of underarm itching are due to noncancerous skin conditions.

However, lymphomas and inflammatory breast cancer (IBC) are two types of cancer that may cause underarm itching.

Lymphoma

Lymphocytes are white blood cells that help to protect the body from infection and disease. Lymphoma is a cancer that can affect these cells. There are many different types of lymphoma. The two main types are Hodgkin lymphoma and non-Hodgkin lymphoma.

Itching can affect people with Hodgkin lymphoma but is less common in people with non-Hodgkin lymphoma. Itching occurs due to chemicals called cytokines, which can irritate nerve endings in the skin. The immune system releases cytokines in response to lymphoma cells.

Itching may occur at locations where there are lymph nodes. Hundreds of lymph nodes exist at different sites throughout the body, including in the armpits.

Other places that may itch include the areas of skin affected by lymphoma and the lower legs. In some cases, itchiness may affect the whole body.

Other symptoms of lymphoma include:

Inflammatory breast cancer

IBC is a rare type of breast cancer that may cause itching of the breast and surrounding areas.

Other symptoms of IBC include:

Breast tenderness, warmth, swelling, and itching can be signs of less severe illness, such as an infection rather than cancer.

In these cases, if there are no other symptoms, a doctor may prescribe a course of antibiotics.

If symptoms do not improve within 7–10 days of antibiotic treatment, people should return to a doctor who can arrange tests to check for signs of cancer or another condition.

Learn more about IBC.

The following six conditions are more common causes of underarm itching.

Intertrigo

Intertrigo is a rash that develops in the folds of the skin. Intertrigo occurs when heat and moisture become trapped between the skin folds, resulting in the growth of yeast, fungi, or bacteria.

The rash itself is usually red or brown and may itch or burn.

Intertrigo commonly develops in the armpits. It may also occur in the following areas:

  • in the crease of the neck
  • beneath the breasts
  • beneath the belly
  • in the groin
  • between the toes

A doctor may prescribe a topical steroid cream to ease itching and irritation. They may prescribe an antibiotic or antifungal cream to clear the infection in severe cases.

Eczema

The term eczema refers to a group of conditions that cause skin irritation. The most common symptoms are itchiness, color changes, and inflammation. These may occur anywhere on the body.

Some people may also find that eczema affects their skin in other ways. Other skin symptoms may include:

  • dryness
  • sensitivity
  • swelling
  • oozing or crusting
  • darkened patches
  • rough, leathery, or scaly patches

Although eczema has no cure, some treatments and strategies can help relieve symptoms and prevent the condition from worsening.

People should visit a doctor or dermatologist for a diagnosis and to discuss possible treatments.

Irritant contact dermatitis

Irritant contact dermatitis (ICD) is a type of eczema. ICD occurs when the skin comes into contact with an irritant.

The condition can develop from a single exposure to a toxic substance or repeated exposure to an irritating substance.

Any substance that comes into contact with the underarm area has the potential to irritate. Examples include:

  • water
  • soaps
  • razors
  • deodorant
  • fabric detergent
  • fabric softener

Itching, burning, and stinging are common symptoms of ICD. In severe cases, the skin may crack and bleed.

People who suspect they have ICD should contact a doctor who will likely prescribe treatments to heal the skin and prevent the condition from worsening.

Learn more about the triggers and treatment options for contact dermatitis here.

Heat rash

Heat rash, or miliaria, is a skin irritation that usually occurs in hot, humid weather.

Heat rash occurs when the sweat glands clog up and cannot release sweat. Water trapped within the glands causes them to swell. This results in a painful itching or prickling sensation.

Heat rash usually appears as a cluster of small pimples or blisters. The clusters commonly occur in the armpits and other places where skin touches the skin.

Areas where heat rash may occur include:

  • the neck
  • beneath the breasts
  • in the creases of the elbows
  • around the groin

Heat rash usually resolves once the skin has cooled. Applying cold compresses and wearing loose clothing can ease skin irritation.

Sometimes, a doctor may prescribe a lotion to help relieve pain and discomfort.

Hyperhidrosis

Hyperhidrosis is a condition in which the sweat glands produce an excessive amount of sweat.

This condition may affect sweat glands across the entire body or those in specific areas, such as the armpits.

Although hyperhidrosis can cause embarrassment and discomfort, it is a relatively harmless condition. However, hyperhidrosis increases the risk of fungal infections, which can cause underarm itching.

Hygiene practices

The armpits are home to many different bacteria. Unsatisfactory hygiene practices can lead to a buildup of sweat and dirt on the skin, which causes these bacteria to multiply and may result in itching.

Keeping the underarms clean is important for preventing itchy armpits.

People should speak with a doctor if they think their underarm itching could be a sign of cancer. Some cancers are more treatable when detected early.

People should also consult a doctor if concerned about the following:

  • a bacterial or fungal infection
  • a skin condition, such as eczema or dermatitis
  • persistent heat rash

A doctor will examine the underarm and will prescribe any necessary treatments.

Sometimes, a doctor may refer the person to a dermatologist for specialist treatment.

Many causes of itchy armpits are preventable.

The following tips may help prevent bacterial and fungal infections:

  • keeping the skin cool and dry
  • showering after exercise
  • drying the underarms thoroughly after showering or bathing
  • wearing sleeveless vests or loose-fitting T-shirts
  • wearing breathable and absorbent materials, such as cotton

The following tips may help alleviate symptoms of underarm eczema:

  • avoiding soaps and deodorants that contain harsh chemicals
  • avoiding shaving with a dry razor
  • using a gentle patting motion to dry the skin
  • using fabric detergents for babies and people with sensitive skin
  • avoiding scented fabric softeners

Itchy armpits are usually a sign of a noncancerous skin condition. Common examples include skin infections or chronic skin conditions such as eczema. A doctor will be able to provide treatment for these conditions.

Rarely, itchy armpits may be a sign of cancer. Lymphoma and IBC are two cancers that can cause underarm itching.

People should contact a doctor if underarm itching and other concerning symptoms occur.