What Can Cause an Armpit Lump?

An armpit lump can have a variety of causes and should be examined by a doctor in order to obtain an accurate diagnosis. Some of the most common causes of the development of an armpit lump include infection, shaving, and the use of antiperspirants. Vaccinations, abscesses, and some forms of cancer may also lead to the presence of a lump in the armpit. Treatment depends on the underlying cause of the lump and may range from simple observation to more invasive methods of treatment, such as chemotherapy or surgical intervention. Any specific questions or concerns about the presence of a lump in an individual situation should be discussed with a doctor or other medical professional.

Shaving can cause the development of an armpit lump. This is usually due to the presence of an ingrown hair, although irritation caused by shaving can also lead to the development of a lump. While shaving can cause a lump to develop under the arm at any age, this is most common among adolescent girls as they learn how to properly shave this area of the body. Antiperspirants have been linked to the possible development of lumps in the armpit, so those who are prone to this occurrence may need to switch to a deodorant that does not contain an added antiperspirant.

Some vaccinations may cause temporary swelling of the lymph nodes under the arm, resulting in the presence of an armpit lump. The vaccines that are most likely to have this side effect include the typhoid vaccine and the measles, mumps, and rubella vaccine. Lumps caused by vaccinations should go away on their own within a few days. If the lump remains for longer than a week, it may be wise to have it examined by a doctor.

Infections are among the leading causes of the development of an armpit lump. Mastitis is a common type of infection that develops primarily among breastfeeding women. Infections caused by cat scratch disease, mononucleosis, or chicken pox may also cause a lump to develop under the arm. These infections can lead to sores known as abscesses, which may need to be cut open and drained by a doctor. Some cancers, including leukemia, lymphoma, and breast cancer, are prone to causing one or more lumps in the armpit.

Treatment for an armpit lump depends on the underlying cause. Most infections can be successfully treated with a round of prescription antibiotics. Lumps that occur due to shaving or antiperspirant use may be treated by warm compresses and discontinuation of any products contributing to the development of the lump. Chemotherapy or surgical intervention may be necessary for lumps that are caused by cancer.