Most of the time, itchy armpits are a sign of irritation, infection, or a skin condition, such as eczema or dermatitis. In rare cases, however, itchy armpits may be a sign of cancer.
This article describes two types of cancer that may cause itchy armpits. We also outline six less severe causes of underarm itching, along with tips on how to prevent itching, and when to see a doctor.
Most cases of underarm itching are due to noncancerous skin conditions.
Lymphocytes are white blood cells that help to protect the body from infection and disease. Lymphoma is cancer that affects these cells.
There are many different types of lymphoma. The two main types are Hodgkin lymphoma and non-Hodgkin lymphoma.
Itching affects around 33% of people with Hodgkin lymphoma and some 10% of people with non-Hodgkin lymphoma.
Itching occurs due to chemicals called cytokines, which 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. There are hundreds of lymph nodes at different sites throughout the body, including in the armpits.
Other places that may itch include:
- areas of skin affected by lymphoma
- 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:
- a swollen or enlarged breast
- a feeling of warmth or heaviness in the breast
- pain or tenderness in the breast
- skin changes on the breast, such as swelling, thickening, or dimpling that resembles orange peel
- redness that covers more than a third of the breast
- a retracted or inverted nipple
Breast tenderness, warmth, swelling, and itching are often 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 go back to their doctor who can arrange tests to check for signs of cancer or another condition.
The following six conditions are more common causes of underarm itching.
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. In severe cases, they may prescribe an antibiotic or antifungal cream to clear the infection.
Some people may also find that eczema affects their skin in other ways. Other skin symptoms may include:
- oozing or crusting
- darkened patches
- rough, leathery, or scaly patches
Although there is no cure for eczema, some treatments help to 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:
- 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 see a doctor who will likely prescribe treatments to heal the skin and prevent the condition from worsening.
Heat rash, also known as miliaria, is a skin irritation that usually occurs in hot, humid weather.
Heat rash occurs when the sweat glands clog up and are unable to 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 in other places where skin touches 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.
In some cases, a doctor may prescribe a lotion to help relieve pain and discomfort.
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.
The armpits are home to many different bacteria. Poor hygiene practices can lead to a buildup of sweat and dirt on the skin, which causes these bacteria to multiply.
Keeping the underarms clean is important for preventing itchy armpits.
People should see a doctor if they think that their underarm itching could be a sign of cancer. Some cancers are more treatable when detected early.
People should also see a doctor if they are 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.
In some cases, a doctor may refer the person to a dermatologist for specialist treatment.
Many causes of itchy armpits are preventable.
The following tips may help to 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 to 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 a chronic skin condition 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 see a doctor if underarm itching occurs alongside any other worrying symptoms.